Laser enrichment device, system, and method for poultry

ABSTRACT

Key words: broiler, environmental enrichment, well-being, lameness, behavior

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to provisionalapplication Ser. No. 62/744,517 filed Oct. 11, 2018, herein incorporatedby reference in its entirety.

GRANT REFERENCE

This invention was made with government support under USDA/NIFA grantno. 2019-69012-29905. The Government has certain rights in thisinvention.

I. BACKGROUND OF THE INVENTION A. Field of the Invention

The invention relates to poultry raising and maintenance and, inparticular, to apparatus, systems, and methods to promote improvedpoultry health and welfare from initial growth stages to adulthood bytechnological enrichment techniques.

The invention described here is a laser device used to stimulatepoultry's natural predatory and visual oriented instincts to hunt andchase bugs or other small moving objects. The goal is to add anenrichment option for poultry producers to comply with guidelines aswell as improve poultry health and welfare. An increasing subset ofbroiler and poultry companies in general are now requiring producers toprovide two separate enrichment options to poultry. Our device is novelbecause current enrichment devices are physical barriers such as perchesor mazes, straw bales, field tile, cans, etc. Our device and method usea mounted laser in the poultry building or other environment that turnson at specific intervals and projects a dot that moves randomly aroundthe floor or other surface. Other light sources that produce aneffective relatively small-in-size light spot or dot on a surface arepossible. This emulates poultry natural predatory behavior and theychase the light spot, as they are visual feeders. We are not aware ofform of enrichment that meets this behavioral and mental stimulationneed. Importantly, this light-based enrichment device and method do notprovide an inanimate source for bacteria, vinuses, spores, or any otherpathogenic growth as it is not a physical object poultry interact with.The birds cannot deposit bodily fluid, feces, or dander on the device asthey would with any of the physical enrichment devices currently used inpoultry production. Birds can deposit bodily fluids, dander, orsecretions on bales or perches, for example, and then this becomes apoint for further propagation of infection for diseases such as avianinfluenza, respiratory disease, coccidiosis, etc. Perches, mazes, strawbales, and field tiles can bring in pathogens if not properlydisinfected before being placed in the housing system. Therefore,additional inanimate objects inadvertently become a biohazard risk inaddition to their intended use as an enrichment. An additional benefitof this device is that producers or workers are able to move around thebuilding uninhibited for flock health checks and building cleanout withan unobstructed view, and the device does not need to be replaced witheach flock. It is a long-term solution for enrichment once installed. Wehave experimental data that suggests a benefit to poultry due to thisenrichment device and method.

B. Problems in the State of the Art

No prior art describing an invention of this type for this specificpurpose is known to the inventors. Previous work has mentioned changinglighting systems to add enrichment, but not in this fashion. Previouslypublished work did not achieve the outcomes that we did as reportedhere.

We know from previous research that birds are visually motivated andapply this to foraging, hunting and feeding behaviors. Furthermore, theycan distinguish color and have demonstrated learning towards items intheir environment See, e.g., Zylinski, S. & Osorio, D. Visual contrastand color in rapid learning of novel patterns by chicks. J Exp Bio, 216,4184-4189, doi:10.1242/jeb.085001 (2013); Osorio, D., Jones, C. D. &Vorobyev, M. Accurate memory for colour but not pattern contrast inchicks. Curr Biol 9, 199-202 (1999); Roper, T. J. Responses of DomesticChicks to Artificially Colored Insect Prey—Effects of PreviousExperience and Background Color. Anim Behav 39, 466-473, doi:DoiJ0.1016/S0003-3472(05)80410-5 (1990), each incorporated by referenceherein as background information.

The bird is an omnivore, and seeks out both crawling and flying insects,small reptiles, and mammals as part of their diet. Furthermore,increasing a chick's ability to find and successfully eat and drink inthe first few days of life is critical to chick welfare and futureproduction.

Research shows that physical activity improves leg lamenesses SeeBizeray, D., Faure, J. M. & Leterrier, C. Making broilers walk: what forand how. Prod Anim 17, 45-57 (2004), incorporated by reference herein asbackground. Yet, only one published study by Bizeray and colleagues(Bizeray, D., Estevez, L. Leterrier, C, & Faure, J. M. Effects ofincreasing environmental complexity on the physical activity of broilerchickens. Appl Anim Beh Sci 79, 27-41. (2002), incorporated by referenceherein as background) used a spot-light light treatment, projectingrelatively large (more light than a light spot or dot) brightly coloredmoving lights on the pen floor daily throughout rearing. The authorsnoted that this lighting treatment did not affect foraging andlocomotion; however, birds in the light treatment spent more time eatingthan control birds. The authors concluded that “moving lights . . . needfurther investigation to establish their effect on behaviour andhealth.” Several reasons as to why this study was not successful are asfollows; the size of the spotlight as seen by the birds on the floor wastoo large, brightness/color was not in the birds UV spectrum, and thelight moved too slow and in a straight line. All of these added togethermay not have stimulated the bird.

With our environmental enrichment concept using guided lasers emulatingnatural behaviors (pecking, moving objects, insect foraging), we believewe therefore have a concept that has not been previously tested ordemonstrated to solve or improve over the challenges and deficiencies ofstate-of-the-art approaches.

The inventors have therefore identified room for a technologicalimprovement in this technical field.

II. SUMMARY OF THE INVENTION A. Objects, Features, and Advantages of theInvention

A principal object, feature, or advantage of the present invention ismethods, systems, and apparatus that improve over or solve problems anddeficiencies in the state of this technical field.

Other objects, features, and advantages of the invention includemethods, systems, and apparatus which utilize specifically controlledlaser spot movement relative to poultry to provide at least one or moreof:

-   -   a. increased expression of natural foraging and feeding        behaviors;    -   b. improved leg health;    -   c. reduced or at least not adversely affect other morbidity        factors;    -   d. reduced number of culled/mortality birds;    -   e. bird enrichment at least consistent with industry and        government guidelines and/or laws and recommendations for        poultry;    -   f. improved growth rate, feed efficiency, and economic return;    -   g. improved animal welfare;    -   h. a source of enrichment that stimulates birds in categories        separate from other current enrichment options;    -   i. use over a wide range of conditions, including but not        limited to, in any and all natural life stages of poultry (e.g.        early life, growing stages, egg production, adult), in different        environments (e.g. pens, buildings, areas), for different        intended therapeutic purposes (weight gain, health, welfare,        etc.), and for different end-uses of the poultry (e.g. meat        production, egg-laying, breeding, etc.);    -   j. scaling up or down depending on application, including in        terms of number of apparatus, number of poultry served, and        options and features;    -   k. high flexibility in placement and operation;    -   l. reuse/repurpose for multiple flocks, growing seasons, or        locations;    -   m. improved animal activity;    -   n. influencing of conspecifics;    -   o. increased percent and duration in time active.

These and other objects, features, aspects, and advantages of theinvention will become apparent from the accompanying description andclaims herein.

B. Aspects of the Invention

One aspect of the invention is projecting one or more light beams onto asurface at and around a plurality of poultry, and automaticallymanipulating movement of a relatively small light spot from each beamaround the surface in an effective way to provide for at least one ormore the objects, features, or advantages discussed immediately above.

In one example, the spot movement can be related to a randomized spotmovement correlated to experimental data establishing one or more of theforegoing. For purposes of this description the term randomized willmean both randomized and pseudo-randomized. In one specific example, therandomized spot movement emulates one of insect movement or typicalpoultry pecking/foraging behavior. In another example, the randomizedspot movement can be controlled in a spatial manner relative to a rewardfor the poultry, such as feed supply or access to a feeder. In anotherexample, the randomized spot movement can be tuned relative to a goaland a species of poultry in terms of one or more of:

-   -   a. spot size;    -   b. spot color;    -   c. spot movement path;    -   d. spot movement speed;    -   e. spot movement time.

In another example, the foregoing spot movement can be presented topoultry in timed sessions, including plural timed sessions per giventime period. In one specific example, each timed session is a fewminutes, presented multiple times a day at equally-spaced-apartintervals.

Another aspect of the invention comprises an apparatus, system, andmethod for raising or maintaining poultry includes one or more lasersthat are controllable to project light beams that produce relativelysmall spots onto a surface. In one example, a control circuitautomatically projects the beams and adjusts aiming of the beams inrandomized fashion to cause the light spots at a floor or surface wherethe poultry are to move around during predetermined sessions during theday. Each light beam and its spot's movement are designed to promote,inter alia, health, behavioral and overall welfare benefits. For birdsin an enclosure, the method, system, or apparatus do not add extraneousobjects to the enclosure, which can create biohazards for the birds orobstacles for humans and can be programmed for operation according toneed or desire. Surfaces could include floors, walls, ceilings, orobjects, whether a part of an enclosure or not.

Another aspect of the invention comprises an apparatus for projectingone or more beams to produce one or more relatively small light spot,including in any of the manners discussed above. In one example, one ormore laser sources are associated with one or more actuators that canchange the beam axis of each laser source. Alternative light sources canbe configured to produce light beams that generate similar light spotson a surface to that of lasers. A controller instructs the one or moreactuators to change beam axis position relative to space in a randomizedpattern for a selected session or sessions of operation. Optionally, anenclosure could contain the components and be mountable relative thepoultry to allow the projection of the beam(s) from the source(s) to asurface at and around the poultry. The randomized movement can beprogrammed to follow any number of different regimens. Non-limitingexamples of programmable variables include path direction(s),starts-stops along path, distances between starts and stops, speedbetween starts and stops, nature of the spot between starts and stops.

Another aspect of the invention comprises a system for projecting one ormore laser beams or other light beams to produce light spots on asurface, including in the manners and with the apparatus discussedabove. The system would include a controller that can be programmed andreprogrammed, as desired, to move the one or more spots relative to oneor more enclosures containing poultry or surfaces that are in thepresence of poultry. The system can be provided to a poultry producer ormaintainer to install and use for poultry enrichment. The system canprovide the producer a number of benefits, including but not necessarilylimited to:

-   -   a. heavier birds (e.g. broilers) for more commercial value per        input costs;    -   b. healthier birds for more commercial value for each set of        produced poultry per input costs;    -   c. less bird mortality for more commercial value for each set of        produced poultry per input costs, and    -   d. compliance with laws, regulations, and/or guidelines for        poultry enrichment.

III. BRIEF DESCRIPTION OF THE DRAWINGS

The appended drawings consist of Figures, which help illustrate certainconcepts of aspects of the invention.

FIGS. 1A, 1B, 2, and 3 are highly diagrammatical illustrations ofconcepts according to aspects of the invention. FIG. 1A is adiagrammatic perspective view of an device and system according to anexemplary embodiment of the invention including a housing with at leastone laser source that can be manipulated in direction and operation toeach project a laser beam to produce a laser spot on a surface, such asa poultry pen floor. FIG. 1B is a diagrammatic perspective depiction ofa plurality of the devices of FIG. 1A installed to project lasers to aplurality of different poultry pens according to aspects of theinvention. FIG. 2 is a diagrammatic plan view of a poultry pen floorillustrating controlled movement of a laser beam spot across the flooraccording to aspects of the invention. FIG. 3 is a flow chart of amethod of controlling a laser beam spot relative a surface according toaspects of the invention.

FIGS. 4A and 4B are graphs illustrating experimental efficacy ofmethodology according to an Example 1 exemplary embodiment of theinvention relative to poultry comprising increasing performance ofbroilers exposed to a regimen according to aspects of the presentinvention.

FIG. 5 is a photograph illustrating experimental method related to anExample 2 exemplary embodiment of the invention. In particular, itillustrates a digital human-approach paradigm (HAP) week 1 image usedfor evaluation. The numbered circles relate to: 1Bird 1: Interacting;Bird 2: Not interacting; Bird 3: At drinker; Bird 4: At feeder; Bird 5:Other.

FIGS. 6A-D, 7A-D, 8A-B, 9A-E, and 10A-E are graphs illustrating efficacyof Example 2 associated with the experimentation method of FIG. 5.

FIGS. 11A-B, 12A-B, 13A-B, and 14A-B are graphs illustratingexperimental method and proof of concept from an Example 3 exemplaryembodiment according to the invention, in particular, laser followingresults showing influencing of conspecifics by a subset of poultryfollowing moving light spots.

FIGS. 15-28 are graphs and experimental data illustrating further proofof concepts according to aspects of the invention.

IV. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION A.Overview

For a better understanding of the invention, a few examples of forms andembodiments the invention can take will now be set forth in detail. Itis to be understood these examples are neither inclusive nor exclusive.

For instance, the examples that follow focus on broilers as the speciesof poultry (birds bred and raised for meat production). However, as willbe appreciated, aspects of the invention extend to the raising ormaintenance of birds for other purposes, and other poultry speciesincluding but not limited to all ages of turkeys, laying hens,pheasants, quail, and other game, fowl, meat, breeding, and productionbirds, including but not necessarily limited to geese, ducks, pea fowl,and bantams, raised in any type of production method or system,including commercial and backyard non-commercial flock.

Some examples are discussed in the context of two laser beams. As willbe appreciated, aspects of the invention can be effective with just onelaser beam or more than two. As a practical matter, the system can bescaled up or down but in the context of a 1.2 m×2.4 m pen withapproximately thirty birds, two laser spots have been found to beeffective. As will be appreciated by those of skill in this technicalarea, the invention can be applied to a wide variety of environments.This includes but is not limited to different types of enclosureswhether pens, cages, or the like, or larger confinements such as barns,buildings, or lots. But it also includes such things as backyards,aviaries, or more open places if there are one or more surfaces uponwhich a laser beam spot can be projected and visually seen and followedby the relevant birds (e.g. simply a floor or the ground, or even awall, ramp, or structure).

It will be appreciated by those skilled in this technical art that lightspots at least similar to laser spots can be generated with lightsources other than lasers. Such light sources either naturally or withoptics can be configured to produce substantially collimated beams fromthe distances discussed herein so that relatively small light spots areproduced on a surface. By relatively small it is meant on the order ofsize of quite small bugs or insects (e.g. on the order of 1 mm inlongest dimension) to other bugs, insects, or animals that are ofinterest as food to poultry (e.g. on the order of 1 mm to 35 mm inlongest dimension, and sometimes for some poultry even larger). All ofthese examples are relatively small in comparison to, for example, spotlights on a surface of the diameter and nature such as discussed inBizeray, D., Estevez, L. Leterrier, C, & Faure, J. M. Effects ofincreasing environmental complexity on the physical activity of broilerchickens. Appl Anim Beh Sci 79, 27-41. (2002), discussed earlier. Suchspot lights are analogous to spot lights used in theatres or arenas toilluminate a substantial area. As such, light spots in these examples ofaccording to invention are not spot lights in the context of Bizerary,et al., Appl Anim Beh Sci 79, 27-41. (2002).

It will also be appreciated that at least many of the exemplaryembodiments describe movement of the light spots as randomized. This isin the ordinary meaning of the term as such movement is not completelydeterministic. Thus, as in its ordinary meaning, it can include one ormore randomized parameter variations in the variation of aimingdirections of a beam that produces a light spot on a surface near therelevant poultry. The extent of randomization can vary. As such, theterm randomized includes completely random, quasi-random, andpseudorandom, all of which are considered randomized because theyexhibit some level of statistical randomness even though the latter twospecies may have some aspect or variable created by a deterministicalgorithm. In some embodiments, this randomized movement emulates theunpredictable movement of a bug or insect crawling on the ground. It canvary in speed, direction, and starts-stops over time. Its movementcannot be predicted in advance given available information. As is knownto those skilled in this technical field, control of actuators that canchange aiming direction of a light source's beam can be randomized by analgorithm or control process that instructs the actuator as to itsmovement. This can be done in a variety of ways.

It will be understood by those skilled in this technical field that anumber of variations are possible to practice the general aspects of theinvention, and that such variations are a part of the invention.

B. Generalized Examples

1. Apparatus

As indicated above, at a general level (as diagrammatically illustratedat FIG. 1A), one way an apparatus (indicated generally at ref. no. 10)according to aspects of the invention can be practiced is as acombination of the following components: (a) one or more light sources20 (e.g. laser sources or other), (b) an actuator or actuators 22 thatcan automatically control aiming direction of the beam of each lightsource relative a reference direction to produce a light spot on asurface at or about poultry; and (c) a controller or control circuit 24that provides motion-control instructions to the actuators in a regimenthat is correlated to efficacy of one or more of the benefits discussedherein relative to poultry health, welfare, or commercial value. In oneexample, there are plural laser sources, each driven according to apre-determined aiming direction relative to time, speed of movement, anddirection of movement.

A specific regimen is discussed in the specific example below. Theapparatus facilitates a practical device to accomplish the same forproducers. The system provides a combination of components toefficaciously accomplish one or more objects of the invention.

As a general matter, one or more lasers can be mounted in associationwith some sort of actuation device having motion control that can adjustthe lasers aiming direction relative to the floor or other projectionsurface. As such, the specifics can take many different forms orembodiments. Specifics regarding lasers or other light sources, andactuators, as well as mounting structures or housing will be set forthin additional non-limiting examples below. Some sort of controlcomponent would allow automation of on and off times for the lasers,randomized adjustment of aiming directions, and other operatingparameters.

The foundational concept is an apparatus that would be effective toproject light beams to create light spots that randomly move around thefloor of the pen or other surface in the presence of one or more poultryat predetermined times.

2. Method

As indicated above (with further reference to FIGS. 2 and 3), amethodology of promoting one or more of the benefits discussed herein isnow discussed. At a general level, a laser or other light source isautomatically controlled to project its beam to a poultry enclosurefloor or other surface at or near poultry to produce a light spot on thesurface, and then move the light spot around the floor or surface in arandomized fashion.

As diagrammatically indicated at FIG. 2, in one example, the lasersource can be controlled so that the projected beam spot 21 on a penfloor moves in different directions across at least part of the floor.The spot can vary in direction, speed, start/stop, or in any fashiondesired by the designer of the system. The path of FIG. 2 is shown tosuggest such variable, but the actual path can vary. It is not necessarythat the path be linear segments. They could be changed in non-linearways. In some embodiments, the laser spot can be projected ontonon-horizontal surface (e.g. walls, objects, containment screens, cages,feeders, watering systems, or netting, etc.). Other light sources thatproduce a similar light spot are possible.

At a general level, the method comprises automatically presenting togrowing, at maintenance, or breeding poultry for pre-determined repeatedsession times each time period (e.g. day), randomized moving light spotsat or near the poultry from spatially and temporarily controllable lightsources (FIG. 3). The spot movement promotes one or more benefits topoultry or the poultry producer outlined herein as shown to beefficacious by experimental data by, e.g., programming an actuator tostart to move the spot(s) and then, over a selected time period, changedirection of movement and stop/restart movement in a randomized fashion.As such, the spot movement is controlled in the sense that a mechanicalor electro-mechanical force changes the optical axis of each light beamover time. But it is randomized in several possible ways. For example,the control can be intentionally other than linear or fullydeterministic in terms of direction, speed, or movement. As indicated atthe non-limited example of FIG. 2, spot movement could vary in one, morethan one, or all of those senses. Another example is that the controlcould be other than repetitive. By techniques known by those skilled inthe art, any of starting point, direction, speed, movement, and endingpoint could be continuously varied over a single session or betweensessions. In the extreme sense of the term, control could be fullyrandom. For example, control signals or instructions that cause changein laser beam aiming direction could be intentionally varied in arandomized fashion. This is, for example, possible such as with randomnumber generators as one of the control inputs to a digitally controlledactuator.

A specific spot movement regimen is discussed in the specificnon-limiting example below but can be varied according to need or desireof the designer. It is to be understood that method efficacy does notrequire all possible benefits or goals be achieved, but that one or morecan be.

As indicated above, a method according to the invention promotes variousbenefits to raising poultry in an enclosure or on a surface bypresenting to poultry the randomized light spot movement on the surface(e.g. floor, walls, or feeding/watering system) at predetermined times.The spots (sometimes herein also called dots) are designed to draw theattention of poultry. In one embodiment of the invention, the randomizedmovement is intended to emulate movement of insects. In others it is tosimply promote the birds to follow the dots as they move. In another, itis to promote some trained response from the poultry. In another, it isto promote movement in a minority of the birds that influencesconspecifics to move.

In one example, a feeding station in an enclosure is accessible by allthe birds. Each light spot movement session begins with randomizedmovement away from the feeding station but eventual migration towardsthe feeding station. This combined system promotes bird training tofollow the dots to promote the benefits that follow from the same.

A system according to one specific aspect of the invention includes apair of 1.2×2.4 meter (m) poultry pens 1, 2, . . . , n and floors ofeach. It is to be understood that this pen-size is but one example only,and that typically production enclosures are much larger. One examplewould be a building or an area of a building on the order of ˜12-15 mwide and ˜122-183 m long. Another example would be a circular buildingor area of ten or more meters in diameter. Other examples are lotshaving areas of ten or more meters in length and width. To the extentthis description refers to pens on the order of ˜1.2×2.4 m, it is byexample only, and the reader will understand that the concepts ofinvention can be applied in analogous ways to other enclosures or areasfor poultry, both larger and smaller. Similarly, the system can bescaled up or down not only in size or area for the one or more groups ofpoultry to move, but also in the number of lasers or otherbeam-producing sources to service such different sized areas. Forexample, the invention pertains to a single laser or other beam sourcefor a relatively small (several feet by several feet) area all the wayto a plurality of lasers or other beam sources effective to service aplurality of different areas or substantially large (e.g. hundreds offeet by hundreds of feet) areas.

Housing 12 (FIG. 1A) can be a sheet metal enclosure. But as can beappreciated this is a non-limiting example only. The housing can takemany configurations and be made of many materials that are durable andwashable for the intended uses discussed herein. Plastic is anothernon-limiting example. A lens which is transparent to the laser beam(s)(reference numeral 13) can cover the beam exit side of the housing toenclose it and protect it from the elements. Electrical power can bethrough a conventional electrical cord to an electrical power source.

By reference to FIG. 2, one non-limiting illustration of sequentialrandomized laser or other light spot movement relative the floor of apen is shown. In this example, at least one original light dot startsout towards the outer margin of each pen and away from a food source ata starting time to an ending time of a predetermined period for therandomized dots (see starting point in upper left corner of FIG. 2).Movement of the dot from the original starting point through subsequenttimes follows a randomized movement and migration towards the feedsource (see arrowed path from upper left corner to lower bottom of FIG.2). Of course, the movement patterns can vary and do not always includestarting at the outward aspect of the enclosure and may not move towardsfeed or water sources. Importantly, the movement, path, speed, spotcharacteristics can vary according to need or desire of the designer.FIG. 2 is but one non-limiting example.

One example of how a designer could program spot movement would beemulation of random insect movement. By empirical methods, the designercould watch actual such insects or video of the same, and emulatestarts/stops, path, speed, etc. For example (for at least some insects)every fraction of a second there could be a fraction of an inch (or justseveral cms) movement that changes direction, starts/stops, or otherwiseis designed to emulate a relevant insect. That direction can even crossback over its former path, remain in one spot for a period of time, orfollow any random pattern. Parameters related to speed, direction, andtime can be manipulated or even changed from session to session. Theycan vary over a single session. In other words, part of the randomizedmotion could be change in speeds along with change in direction duringsingle or multiple sessions. On the other hand, however, it is possiblefor the designer to invent a spot movement based on criteria of thedesigner's choosing.

Further, a methodology according to one aspect of the invention caninclude mounting the laser or other beam source unit in a mannerallowing the beam movement range and aiming direction to cover at leasta substantial part of the floor or surface. Pre-programming regardingpredetermined periods scheduled during the day for light spot sessionscan be selected. Days may even be skipped. In one non-limiting exemplaryembodiment, four different sessions of four-minutes each during a24-hour day are automatically instigated by the circuit. This meansthose four-minute sessions will be at spaced apart 6-hour periods. Aswill be appreciated, during each four minute session, speed, direction,and timing of change of direction can be predetermined. In analternative fashion, the programming might essentially change any or allof those parameters from session to session so that the birds in the penwill not be trained for one pattern repeated over and over.

3. System

As indicated at FIG. 1B, a system can use one or more of theabove-described apparatus such as apparatus 10A-n for a regimen ofoperation according to the methodology of promoting one or more of thebenefits discussed herein. This could involve one integrated housing 12of one or more laser or other beam sources 20 with actuator(s) 22 (seeFIG. 1A), or a plurality of such housings 12 distributed around one ormore poultry raising buildings 30. Each building could have one or morepoultry enclosures to segregate sub-sets of poultry (one non-limitingexample being the pens discussed above). A controller 24 can be includedat each housing 12. Alternatively, one controller 24 may be able toinstruct more than one set of laser sources 20.

Therefore, benefits to poultry and/or producer can be leveraged bypracticing the method with many birds. The system can be retrofitted toexisting poultry-raising facilities or installed as original equipment.The mounting can be above the floor, which provides added benefits ofavoiding structures that inhibit poultry or human movement or the riskof pathogenic issues with added structures on the floor or in directcontact with poultry.

A system according to the present invention can include the lasers, theactuators, the controller, a mounting structure to elevate the sameabove a poultry enclosure or projection surface at or near the poultry,and optionally, if part of the methodology, a feeding station.

C. Specific Examples of Exemplary Embodiments

A specific example of an apparatus according to the general apparatusand method and system of FIGS. 1A-B, 2, and 3 is now described.

1. Apparatus

With reference to FIGS. 1A-B, 2 and 3, in a specific embodiment a device10 according to the invention could include a housing 12 (e.g. sheetmetal) of 20.32 cm×20.32 cm×20.32 cm or so in width, height, and depth.It can be essentially box-type form factor (as shown) with one side open(which could optionally be covered by a light transmissive lens 13,e.g., glass or plastic). A mounting interface (e.g. sheet metal flangesor brackets 16, or other) can be designed to allow mounting of housing12 to, e.g., ceiling beams, floor posts, or enclosure frame) above thefloor. This could be nails, screws, bolts, or other techniquessufficient to support the weight of device 10. An electrical cord 18 canextend out of housing 12 for operative connection to an electrical powersource (e.g. household or commercial electric service, or locallygenerated source). But as will be appreciated, the housing can take on anumber of different form factors and sizes depending on the designer'sneeds or desires and the particular application it is put to. Theapparatus design can vary according to the designer's need or desire.There may be benefits to mounting the apparatus on a ceiling or wall asopposed to a dedicated framework for elevating the apparatus. Theapparatus can be mounted to any sufficient supporting structure at ornear the surface to which the laser spots are to be projected.

One or more laser beam sources 20 are mounted inside housing 12. Anactuator or actuators 22 are operatively associated with the lasersources 20 in a manner that the beam-aiming axis from each laser extendsout of lens 13 but can be adjusted by the actuator(s) relative to areference axis out of the lens 13. A control circuit or controller 24can also be inside housing (to protect it from environmental conditionsincluding moisture, dust, and debris) and be configured to instructactuator(s) 22 to change the direction of aiming axis of each lasersource 20 during a time session. It is to be understood that the controlcircuit or controller 24 alternatively could be mounted outside housing12 for easy access such as reprogramming. Some type of mountingstructure or bracket(s) 16 can be associated with housing 12 to allow itto be easily mounted above an enclosure floor. The result of projectionof laser beams from laser sources 20 is a laser spot 21 on the floor.

Specific commercially available examples of certain of the foregoingcomponents are set forth below. It is be understood that these arenon-limiting examples. It will be understood that variations andsubstitutions are possible according to designer's need or desire.

TABLE C1 Manufacturer Component Model No. name/address Laser source 20FH0054 Focusable 650 nm Farhop. Temple 5mW 3-5 V red laser “dot”Terrace, FL module diode w/driver (USA) plastic lens with clam shellpacking (2 pack) Actuator 22 2 DOF Pan & Tilt with Mg Mallofusa 995Servos Sensor Mount for Arduino Robot Set Car Plane DIY with MallofusaCable Tie Controller 24 Uno R3 microcontroller Arduino A000066

The foregoing combination of components results in an apparatus 10 ofrelatively low total weight (e.g. in the range of no more than a fewkilograms) so that each would be easy to elevate and mount.

The manner in which laser source 20 is mounted to an actuator 24, andthen the actuator is instructed to automatically vary the aimingdirection of the laser source to cause the movement of a laser spot on afloor, can be as set forth below.

By reference to the table above and the table below, the followingpartial parts list will be used to describe one implementation of thesystem. Those skilled in the art will be able to assemble and operatethese components according to the descriptions herein.

!TABLE C2 Part description Specific name for order Quantity 2 pack laserFarhop focusable 650 tun 5 mW 3-5 V Red 1 dot diode with Laser ″Dot″module diode (see above) w/ lens driver plastic lens with clamshellpackaging Power adapter Sunfounder DC 9 V/650 mA Powerplug 1 for ArduinoAdapter for Arduino Uno, R3 Mega 2560/ Uno 1280 (~1 meter) Pan & tiltMallofusa 2DOF (see above) DIY with motor Mallofusa Cable Tie 2 Minilaser dot Geebat 10 pcs mini laser dot diode module 1 diode head headred 650 nm 6 min 5 V 5 mV diode 3 way plug-in 3 way socket 1 jumperwires Haitronic 120 pcs 20 cm length JumperWires/ DuPont cablemulticolored 40 pin M to F, 40 Arduino Uno Arduino Uno R3microcontroller A000066 1 extension cord Slimline 2241 Flat plugextension cord, 1 3 wire, 2.4 m., white wall power iMBA Price 5 V DCWall power adapter 2 adapter UL listed power supply (1.5 m., 5 V 2A(2000 mA)) aluminum AixiZ aluminum mount & heat sink for 2 mount 12 mmmodules Timer With 3-prong outlet for appliances, energy 1 saving timer,15 A/1800 W Box Grainger Enclosures, Metallic, 20 cm 1 H x 20 cm W X 20cm D

As will be appreciated by those skilled in this technical area, one wayto implement the system is:

-   -   a. Mount the two Farhop red lasers to the two-degree freedom of        movement (2 DOF) end of the Mallofusa pan & tilt actuator. This        can include encasing each Farhop laser in an AixiZ mount and        heat sink for heat management during laser operation.    -   b. Mount the double laser/pan & tilt actuator into the Grainer        Enclosure box so that the laser aiming axes extend out of the        open side over a desired range of movement.    -   c. Install the Arduino controller into the enclosure and set it        up for programming and operation. This would include use of the        Sunfounder DC power adapter, 3 way plug-in, Slimline extension        cord to a power outlet, and the iMBA Priced wall power adapter.        One skilled in the art would know how to configure to provide        electrical power to all needed components in the enclosure (e.g.        lasers, pa/tile actuator, and controller at the needed        operational electrical power type and levels.    -   d. Connect and program the Arduino controller to instruct        motion-control of the pan/tilt motors according to the        randomized spot movement desired. This would include using the        GenBasic jumper wires, Haitronic jumper wires, and any other        needed components such as would be understood by those skilled        in this technical area. The programming would include an output        from the Arduino controller to the pan & tilt motors to        effectuate the desired laser spot movement relative a surface to        which the Farhop lasers are to be projected.    -   e. The programmable plug-in digital timer would be used here to        start and stop operation of each laser spot random movement        session. It can be easily programmed to start and stop        electrical power to the system according to such a schedule. One        non-limiting schedule is the 4 minute laser spot movement        session once every 4 hours each day, as further discussed        herein.    -   f. The assembled system can be mounted by appropriate fasteners        and brackets in an elevated position relative to the desired        area for the laser spot movement sessions. As will be        appreciated, the tables above indicate to one skilled in the art        other conventional components or techniques one could use when        assembling and initiating the system.

It is to be understood and will be appreciated by those skilled in thistechnical area, that the foregoing is but one non-limiting example.Variations obvious to those skilled in this technical field areincluded.

2. Method

Several methods according to the invention will be discussed in detaillater, including in the proof of concept section. It is to be understoodthat variations are possible according to a designer's need or desire.

Some possible pertinent parameters for the designer of such systems areset forth the table below. Those skilled in the art will appreciate thata range of values of each parameter is possible.

TABLE C3 Parameter Range or details Laser beam spot 21 size several mmdia. Laser spot 21 color ~At least color associated with visiblefrequency but is not limited thereto. Laser spot 21 speed ~0 to 5cm/sec. Laser spot 21 path Randomized (efficacious for benefits ofexperimental results) Laser spot 21 session ~0.5-6 mins/session timeNumber of sessions per 0-10 sessions/day day

In one specific non-limiting example, during one session the parameterscould follow the following pattern:

1. Relatively constant speed while moving but could randomly vary withina range;

2. Randomized direction changes.

3. Intermittent starts/stops.

In the foregoing example, the laser could have the followingnon-limiting characteristics:

1. Red (650 nm central frequency).

2. Spot size of 2 mm diameter.

Of course, these characteristics can be varied according to need ordesire.

3. System

As indicated above, and as intimated by FIG. 1B, in a multiple penfacility, other confinement, or non-confinement husbandry setup, oneapparatus can be used per pen, but as shown, could be shared by pluralpens (e.g. at least 2 pens). This presents economic benefits to theproducer; including in capital costs, installation, and operation. Aswill be appreciated, because projected light beams are used, eachapparatus is not constrained to a single pen.

But, further, plural apparatus 10A-n can be mounted in a facility havingmany pens. In this specific example, each apparatus 10 services twopens, which can reduce expenses by 50% over having one apparatus perpen. This includes cost of the apparatus 10, but also installation,electrical operating costs, and maintenance and repair and replacementover time.

It is again pointed out that the randomized laser spot sessions could beapplied to other environments than these pens, including but not limitedto, larger and different sized pens or enclosures and even indoors oroutdoors general areas, aviaries, and other locations or set-ups. Thedesigner would select the number and types of lasers, the types of lasermovement and characteristics, and placement of the lasers. These couldvary depending on application, including type of poultry and goals ofthe enrichment.

As will be appreciated, the following sections provides further detailsabout exemplary structure and operation according to one or more aspectsof the invention, as well as results of experiments that demonstrateefficacy.

D. Specific Example 1 (Relative to Performance of Broiler Chickenswithout Sacrificing Well-being or Environmental Qualities)

For further understanding of the invention and its aspects, below is anapplication of concepts according to the invention to a particularspecies of poultry, namely broilers, which, as is well known by thoseskilled in this technical art, are chicken bred and raise specificallyfor meat production.

This description is from M Meyer, A K Johnson, E A Bobeck, A novelenvironmental enrichment device improved broiler performance withoutsacrificing bird physiological or environmental quality measures,Poultry Science, Volume 98, Issue 11, November 2019, Pages 5247-5256,https://doi.org/10.3382/ps/pez417 Published: 30 Jul. 2019, which isincorporated by reference herein in its entirety. Exemplary embodimentsof apparatus, systems, and methods according to the invention aredescribed in detail. Proof of concept evidence is also included. Again,however, this is a non-limiting example of the invention. This will helpthe reader further understand objects of the invention by the details ofthis specific example and context.

A Novel Environmental Enrichment Device Improved Broiler Performancewithout Sacrificing Bird Physiological or Environmental Quality Measures

ABSTRACT Modern commercial broilers have been genetically selected forfast growth and heavy breast muscling, contributing to a top-heavyphenotype and increased leg lameness. A quick-growing phenotype coupledwith poor leg health fosters inactivity. The objective of this study wasto stimulate broiler movement using novel environmental enrichment anddetermine the impact of movement on production, leg health, andenvironmental parameters. A total of 1,200 Ross 308 broilers were housedin 40 pens with 30 birds/pen for 6 wk in 2 separate rooms (laserenrichment or control). Each enrichment device was mounted above 2adjoining pens, projected 2 independent, randomly moving laser beams atthe floor to stimulate innate predatory behavior, and was active 4 timesdaily in 4-min periods. Performance outcomes were calculated by pen andaveraged per bird for each performance period and overall days 0 to 42.A total of 70 randomly selected focal birds were examined for breastblisters and footpad dermatitis each week and euthanized on day 42 fortibia quality measures. Air quality and litter moisture were sampled byweek. Laser-enriched pens had greater average bird feed intake instarter (P 0.001), grower (P=0.004), finisher periods (P=0.004), andoverall days 0 to 42 (0.19 kg/bird; P=0.0003). Average bird weight gainwas also increased in enriched pens in each performance period: starter(P=0.043), grower (P=0.001), finisher (P<0.001), and overall days 0 to42 (0.24 kg/bird; P<0.001). Enriched pens had improved feed conversionratio (FCR) vs. control with a decrease of 3 FCR points in the grower(P=0.031), 18 points in the finisher (P<0.001), and 7 points overall(P<0.001). Enriched pens had higher ADG during starter (P=0.048),finisher (P<0.001), and overall (5.7 g/bird/d; P<0.001). No differenceswere found in breast blister, footpad dermatitis, tibia, air, or litterquality measures (P>0.05). In summary, a novel enrichment device basedon bird visual feeding and predatory instincts positively affectedperformance through decreased FCR and increased ADG without sacrificingexternal animal-based measures, tibia quality, or air or litter quality.

1. INTRODUCTION

Due to intense genetic selection, modern broilers weigh 4 to 5 timesmore than broiler lines from the 1950s at the same timepoints, and are 2to 3 times more feed-efficient (Havenstein et al., 2003; Zuidhof et al.,2014). However, this selection for increased growth rate has contributedto up to 30% of modern commercial broilers being affected by leglameness or poor locomotion (Knowles et al., 2008; Bassler et al.,2013). Lame-ness leads to increased time spent lying down, which in turnincreases litter contact and could result in a higher breast blisteroccurrence and contact dermatitis (Weeks et al., 2000; NMs et al., 2009;Bassler et al., 2013). Furthermore, a lack of activity compoundslame-ness by negatively affecting bone strength, mass, and ability tobear weight properly (Lanyon, 1993; Rath et al., 2000). Contactdermatitis-driven tissue damage may be caused by urea in the littergenerating ammonia, creating a chemical burn effect and is likelypainful. The prevalence of this issue, affecting 21.87% of Ross 308broilers in a recent year-long study, may be reflective of air andlitter quality in the house (Haslam et al., 2006; Dinev et al., 2019).The National Chicken Council (NCC, 2017) Animal Welfare Guidelines andAudit Checklist for Broilers require that ammonia in the air neverexceeds 25 ppm at bird height, and litter must be evaluated forfriability and moisture.

Severe lameness hinders birds from accessing feed and water, andnegatively impacts the industry economically, necessitating up to 2%culls in a $30 billion industry (Dunkley, 2007; USDA, 2017). Inaddition, studies have reported that broilers with severe leg lamenesseat more analgesic-containing feed than healthy birds, and birds fed ananalgesic diet showed improved speed of walking, indicating relief frompain and discomfort caused by leg abnormalities (McGeown et al., 1999;Danbury et al., 2000). The 2017 NCC broiler audit guidelines haverecognized lameness as a detrimental welfare issue and recommend gaitscoring 100 birds per flock to evaluate leg health within 1 wk ofslaughter, and footpad scoring 200 paws at slaughter.

Past research in laying hens has shown that restricting exercise had aclear, negative impact on bird skeletal health (Shipov et al., 2010),and work in broilers has shown that motivating physical activityincreased tibia strength and decreased lameness (Reiter and Bessei,2009). Prayitno et al. (1997) concluded that activity driven by redlight, early and late in the rearing period, improved locomotioncompared to a blue light treatment where broilers were less active.Birds are visual feeders and preferred and orange colors over green andblue (Ham and Osorio, 2007). Bizeray et al. (2002) studied the effectsof red, blue, green, and yellow spot-lights moving across the floor butdid not see a change in broiler physical activity, and the authorsconcluded that that the spotlights moved too quickly. Baxter and others(2019) implemented perches and dust baths but did not see an effect ofenrichment on foraging, play, or activity, nor, in a separate paperpublished on the same study, leg health (Bailie et al., 2018). Platformuse by broilers in Norring et al. (2016) likewise did not increaseoverall activity. A study by Jordan et al. (2011) showed that broileractivity and foraging was increased by scattering feed in the litter,but broilers in the enriched treatment had 13% lower weights at harvest.

Certainly, some forms of environmental enrichment have been shown toimprove broiler welfare outcomes, as in Ventura et al. (2012), wherebarrier perches stimulated natural perching behavior and reducedaggressive interaction and rest disturbances compared to the control.Recent work by BenSassi et al. (2019) showed that increasingenvironmental complexity was associated with fewer skin concerns, lowermortality, fewer underweight birds, a lower overall rejection rate athar-vest, and less welfare problems overall. However, an enrichmentoption designed to motivate broiler activity and improve physical andperformance outcomes is still lacking in the published literature. Thus,we developed a novel form of environmental enrichment de-signed tomotivate physical movement through visual stimulation. The objectives ofthis work were to deter-mine the impact on bird physiology (leg lamenessand footpad and breast condition), performance, and environment (air andlitter quality).

2. MATERIALS AND METHODS

All live bird procedures were approved by the Iowa State UniversityInstitutional Animal Care and Use Committee.

a. Animals

A total of 1,260 straight-run Ross 308 broiler chicks (day of hatch; BW47.38±0.14 g) were obtained from a commercial hatchery and transportedto the Poultry Research and Teaching Unit at Iowa State University(International Poultry Breeders Hatchery, Bancroft, Iowa). A total of1,200 broiler chicks were randomly assigned to treatment groups and theremainder were culled. A subset of 70 birds were randomly assigned uponarrival as focal birds, identified with wing bands, and marked withunique animal-safe food coloring (red, blue, green, purple, and black;Wilton, Woodridge, Ill.). Half of the focal birds were assigned tolaser-enriched pens, and half were assigned to control pens (n=5 focalbirds/pen in 14 pens). Food coloring was applied to a cotton ball,rubbed on the back of the chick's head and neck, and reapplied on anas-needed basis throughout the trial.

b. Housing and Feeding

Birds were housed in 40 floor pens (30 birds/pen) measuring 1.22 by 2.44m across 2 rooms in the barn (20 pens/room). One room contained 20enriched pens (exposed to laser device), and the other contained 20control pens, with an anteroom separating the two so no crossover ofenrichment device was possible. Ap-proximately 10-cm-deep fresh woodshavings provided bedding over the solid concrete floor, and polyvinylchloride pipe dividers with mesh walls (1.22 m height) separated pens.High and low temperatures and humidity were monitored daily in theenriched and control rooms of the barn. Average temperatures are listedfrom the starter, grower, and finisher periods respectively from theenriched room: 85.47, 77.39, and 71.71° F., and the control room: 85.53,77.46, and 71.50° F. Average relative humidity is listed from thestarter, grower, and finisher periods respectively from the enrichedroom: 23.86, 27.21, and 33.93%, and the control room of the barn: 19.89,23.93, and 27.75%.

Birds were gradually adjusted from 24 h light on days 0 to 7 (30 to 40lux) to 20 h light (20 to 30 lux) from days 8 to 42. Chicks were broodedwith 2 heat lamps/pen (22.9 cm reflectors with porcelain socket) using125-W heat bulbs (Sylvania, Wilmington, Mass.) for the first week. Birdswere fed an ad libitum diet formulated for Ross 308 commercialrecommendations (Table D1) out of a hanging chicken feeder (BRHF151,Brower Equipment, Houghton, Iowa) gradually raised to accommodate birdheight. Water was provided ad libitum from a hanging nipple water line(8 nipples/pen).

c. Laser Enrichment Device

A total of 10 laser enrichment devices designed and built specificallyfor this research were affixed over 20 pens in 1 room of the broilerbarn. Each device was de-signed and calibrated to cover 2 adjoiningpens. The enrichment device consisted of 2 independent red 650 nm laserscontained within a 20.5 by 20.5 cm metal box with a glass bottom mountedon a custom-designed structure made of 3 wooden beams (2.4 m height)raised above the pens. The lasers projected in the direction of the penfloor and moved in a random pattern at a variable speed between 7.6 and30.5 cm/s for 4-min “laser periods”: 05:30 to 05:34, 11:30 to 11:34,17:30 to 17:34, and 23:30 to 23:34 daily for the entire trial period.Over-head snapshots of the activated laser in the pens were taken forevaluation for days 2, 16, 30, and 37. As this device was novel, andthere is no ex-planation of broiler attention span in the currentliterature, the 4-min length of laser periods was tested with theknowledge that it would need to be validated and may need fine-tuning infuture studies. The decision to expose broilers to laser periods 4times/d was based off work by Jones et al. (2000), which showed thatlaying hens exposed to environmental enrichment in the form of stringsfor limited daily time periods (10 min), rather than constant exposure,maintained interest in pecking the strings for 14 wk.

TABLE D1 Starter, grower, and finisher diets provided ad libitum to Ross308 broilers. Ingredients² Starter Grower Finisher Corn (%) 55.32 58.6962.78 Soybean meal (%) 37.15 33.40 28.59 Soy oil (%) 2.02 2.98 3.97 Salt(%) 0.40 0.40 0.40 DL-Methionine (%) 0.33 0.30 0.27 Lysine HCl (%) 0.250.23 0.21 Threonine (%) 0.15 0.15 0.15 Limestone (%) 1.30 1.01 1.00Dicalcium phosphate (%) 2.05 1.81 1.60 Choline chloride 60 (%) 0.40 0.400.40 Vitamin premix¹ (%) 0.63 0.63 0.63 Calculated values Crude protein(%) 23.05 21.50 19.50 ME (kcal./kg) 3,000 3,100 3,200 Fat (%) 4.59 5.596.64 Digestible lysine (%) 1.30 1.19 1.06 Digestible threonine (%) 0.920.87 0.80 Digestible arginine (%) 1.39 1.28 1.14 Analyzed values (asfed) Dry matter (%) 89.40 89.81 89.23 Crude fat (%) 6.42 7.63 8.74 Crudeprotein (%) 24.17 21.66 19.89 Each diet was fed for 14 D: starter dietweeks 0-2, grower weeks 2-4, and finisher weeks 4-6. Analyzed values arepresented on as as-fed basis. ¹Vitamin and mineral premix provided perkg of diet: Selenium 200 μg; vitamin A 6,600 IU; vitamin D₃ 2,200 IU;vitamin E 14.3 IU; menadione 880 μg; vitamin B₁₂ 9.4 μg; biotin 33 μg;choline 358 mg; folic acid 1.1 mg; niacin 33 mg; pantothenic acid 8.8mg; pyridoxine 880 μg; riboflavin 4.4 mg; thiamine 1.1 mg; iron 226 mg;magnesium 100 mg; manganese 220 mg; zinc 220 mg; copper 22 mg; iodine675 μg. ²Calculated according to NRC (1994).

d. Performance

The 6-wk trial was separated into a starter, grower, and finisher periodthat were 2 wk in length. All birds in each pen were weighed as a group,and then focal birds were weighed individually at the start of eachperiod to determine weight gain. Feed disappearance/intake (FI) wasrecorded throughout. Feed conversion ratio (FCR) and ADG were calculatedby pen and averaged by number of birds in the pen.

e. Breast Blisters and Footpad Dermatitis

Focal birds were examined the same day each week of the trial by thesame researcher, on a different day than birds were weighed, in theirhome pens for breast blisters and footpad dermatitis, with all birdsexamined on day 42. Both examinations took place at the same day andtime each week and were done by the same re-searcher. Footpad dermatitiswas scored pass/fail using the American Association of AvianPathologists Paw Scoring system (2015), where a normal yellow color orslight discoloration with hyperkeratosis on an area less than ½ of thefootpad was scored a pass, and erosions, ulcerations, scabs,hemorrhages, or swelling on an area greater than ½ of the footpad wasscored a fail. Breast blisters were scored on a present/absent basisbased on the methods used by Greene et al. (1985), where blisters wereconsidered present when a blister was equal to or larger than 1.27 cm²,when there were 1 or more breast burns, or when there were scabs onbreast skin. A brownish-colored scab would be considered “mild” and anulcer with black exudates was considered “severe.”

f. Tibia Quality

On day 42, focal birds were euthanized using carbon dioxide and theright tibia was collected from each bird and frozen at −20° C. untilfurther analysis. Tibia (n=70) were thawed overnight, weighed, andscanned using dual energy x-ray absorptiometry (DXA, Hologic,Marlborough, Mass.). The bones were scanned in groups of 7 using thevalidated “rat whole body scan” protocol for bone mineral density (BMD)and bone mineral content (BMC).

Bone breaking strength of focal bird tibia was measured using thetensile test and compression method on an Instron 3367 Universal TestMachine (Norwood, Mass.). The machine had a 30 kN load capacity and 2platons controlled to fracture the bone between them. Each tibia wasindividually fractured in a plastic bag wrapped in cheesecloth toprevent contamination of the machine or slippage due to the bag. Eachtibia was placed on the bottom platon with the lateral/medial condyleend of the bone intentionally placed over the edge, out of reach of theplatons, and the bend of the tibia facing down. The test was set up sothat the top platon moved vertically downwards towards the bone at arate of 10 mm/min and a 15% rate of load. The ma-chine was stopped atthe distinct rapid decline in force (visualized on the monitor) andsimultaneous sound of the bone fracturing. Load (kgf) was recorded atthe point of break and divided by area of tibia (cm², obtained from DXAscanning) to calculate bonebreaking strength as per the manufacturer'srecommendations (Instron; Norwood).

g. Air and Litter Quality

Ammonia in the air (ppm) was measured at bird height in the front,middle, and back of each room on day/wk for weeks 2-6 with a hand-heldammonia monitor (GasAlert Extreme, BW Technologies, Schaumburg, Ill.)and ammonia test strips. The ammonia monitor was titrated every 14 Dwith an ammonia tank and provided an exact value, while the stripspro-vided a range of 5 ppm. Litter quality was analyzed weekly accordingto the NCC Audit Guidelines. Litter moisture was evaluated in 3 randomlyselected pens in the front, middle, and back of each room of the barn.One handful of litter sample was gathered from 3 sections; litter within15 cm of the water line of each pen was intentionally excluded. Litterquality was scored pass/fail by the same researcher weekly; to passlitter must be “loosely compacted when squeezed in the hand. If thelitter remains in a clump when it is squeezed in the hand, it is toowet” (NCC, 2017).

h. Statistical Analysis

In this experimental design, individual control pens (n=20) wereconsidered the experimental units, and laser-enriched pens were analyzedas a group of 2 pens with a shared laser device (n=10). Room within thebarn was confounded by laser treatment, and thus was not included in themodel, but environmental conditions, management, and feeding were keptas identical as possible between both rooms. All data were analyzedusing SAS software version 9.4 (SAS Institute Inc.; 2016). PROCUNIVARIATE was used to assess the distribution of data prior toanalysis. Performance and tibia quality data were normally distributed,and hence were analyzed using PROC MIXED, a mixed linear model, withtreatment as a main effect. Principal component analysis (PROC PRINCOMP) was used to test for redundancy and correlation within the bonequality measures, and then multidimensional preference analysis (usingPROC PRIN QUAL) was performed to visualize the correlation betweenvariables and reduction to 2 components. Air quality measures wereanalyzed using PROC FREQUENCY and chi square to determine thedistribution and association of readings by treatment. For all measures,a value of P 0.05 was considered significant and differences betweenmeans were detected using PDIFF.

3. RESULTS

a. Performance

All performance measures, including FL, weight gain, FCR, and ADG, wereaveraged per bird by each 2-wk performance period and overall (days 0 to42). FI was increased in laser-enriched birds in all periods compared tothe control: 4% increase in the starter, P<0.001; 3.1% in the grower,P=0.004; 5.1% in the finisher, P=0.004; and 3.9% overall, P=0.003 (TableD2). Enriched birds had an increased intake of 5.52 kg/pen overallcompared to the control (P=0.006). Weight gain was also increased inlaser-enriched birds in each performance period when compared to thecontrol: 2.6% in the starter, P=0.043; 5.5% in the grower, P=0.001;13.8% in the finisher, P<0.001, and 7.9% overall, P<0.001 (Table D2).Enriched pens showed increased gains of 7.19 kg/pen overall compared tothe control (P<0.001).

Enriched birds had improved FCRs compared to control birds with adecrease of 3 FCR points in the grower (P=0.031), 18 points in thefinisher (P<0.001), and 7 points overall (P<0.001, Table D2). Whenaveraged per bird, laser-enriched bird ADG was increased by 2.9%(P=0.048) in the starter period, 13.2% (P<0.001) in the finisher period,and 7.9% overall (P<0.001, Table D2), and was increased overall on a penbasis when compared to the control (0.17 kg/d; P<0.001).

TABLE D2 Ross 308 straight run broiler¹ performance outcomes includingfeed intake, weight gain, feed conversion ratio (FCR), and ADG by each2-wk performance period and overall. Performance measure Control² Laser³Pooled SEM P-value Feed intake (kg) Starter 0.48 0.50 0.003 <0.001Grower 1.56 1.61 0.012 0.004 Finisher 2.62 2.76 0.030 0.004 Overall 4.694.88 0.041 0.003 Weight gain (kg) Starter 0.37 0.38 0.004 0.043 Grower1.04 1.10 0.013 0.001 Finisher 1.37 1.59 0.018 <0.001 Overall 2.80 3.040.026 <0.001 FCR⁴ Starter 1.29 1.31 0.009 0.119 Grower 1.49 1.46 0.0080.031 Finisher 1.92 1.74 0.024 <0.001 Overall 1.68 1.61 0.010 <0.001ADG⁵ (kg) Starter 0.0265 0.0273 0.001 0.048 Grower 0.0740 0.0756 0.0010.390 Finisher 0.0992 0.1143 0.001 <0.001 Overall 0.0666 0.0723 0.001<0.001 Starter period indicates weeks 0-2, grower weeks 2-4, andfinisher weeks 4-6. Values presented as LSMeans (pooled SEM) averagedper bird (apart from FCR) with treatment as the main effect. ¹Broilerchicks transported from International Poultry Breeders Hatchery(Bancroft, IA) on day of hatch to Iowa State Poultry Research andTeaching Farm: BW 47.38 ± 0.14 g. ²Control describes pens not exposed tolaser enrichment. ³Birds exposed to laser enrichment device. ⁴FCRcalculated by dividing kilogram of feed by kilogram of bird weight gainper pen, averaged by treatment for each performance period and overall.⁵ADG calculated by dividing bird weight gain averaged per bird by numberof days in each performance period and overall.

b. Breast Blisters and Footpad Dermatitis

Under our research conditions, no control or laser-enriched birdsdisplayed breast blisters or footpad dermatitis.

TABLE D3 Focal bird (n = 70) right tibia quality measures and weight(LSMeans, pooled SEM) using treatment as a fixed effect. MeasureControl¹ Laser² Pooled SEM P-value Bone mineral density³ 0.129 0.1380.005 0.203 (g/cm²) Bone mineral content³ 0.975 1.107 0.078 0.237 (g)Bone breaking strength⁴ 9.941 11.143 0.693 0.225 (kgf/cm²) Right tibiaweight (g) 14.97 15.75 0.470 0.250 ¹Control describes birds from pensnot exposed to laser enrichment. ²Laser describes birds in pens exposedto laser enrichment. ³Tibia were scanned for bone mineral density andcontent using the DXA “rat whole body scan” in groups of 7. ⁴Bones werefractured individually using the compensation method on an Instron 3367Universal Test Machine at a rate of 10 mm/min and a 15% rate of load.The machine was stopped at the distinct rapid decline in force asvisualized on the monitor, and value is presented as load (kgf) dividedby area of tibia (g/cm²).

FIG. 4A shows regression of focal bird tibia (n=70) bone mineral content(BMC, g) and bone mineral density (BMD, g/cm²). Content and density arehighly correlated (r=0.857). 1. Control describes focal birds notexposed to laser enrichment device; 2. Laser describes focal birdsexposed to enrichment device 4 times daily for 4-min laser periods; 3.Bone mineral content and density of the tibia were obtained using theDXA “rat whole body scan” in groups of 7; 4. BMC denotes bone mineralcontent (g), BMD denotes bone mineral density (g/cm²).

c. Tibia Quality

DXA scan results of focal bird tibia showed no changes in BMC or BMD,although the enriched tibia were numerically higher in both categoriescompared to the control (Table D3). BMD and BMC were strongly correlated(FIG. 4A), as were BMC and tibia weight (r=0.720). Interestingly, BMDand tibia weight were only moderately correlated (r=0.479). Bone mineralcontent of the tibia and bird body weight were strongly correlated(r=0.677), but BMD and bird weight were again only moderately correlated(r=0.456).

Bone breaking strength, determined using the Instron 3367 UniversalTestMachine compression method and reported as load (kgf)/area (cm²),was numerically higher in enriched focal bird tibia than control, butthe difference was not significant (Table D3). Bone breaking strengthwas moderately negatively correlated with tibia weight (r=−0.486) andbird weight (r=−0.325). The correlation between all bone measures can bevisualized in FIG. 4B using a multidimensional preference analysis.

d. Air and Litter Quality

The birds started on fresh, dry litter that remained friable throughout,and the litter scored “pass” in all pens for the entire 6 wk (≤20 ppm)the birds were on trial.

Ammonia strip readings taken on a weekly basis were identical in boththe enriched and control rooms of the barn. Before birds arrived, thebaseline ammonia levels were 0 ppm in both rooms of the barn. Theaveraged readings were week 2, 5 ppm; week 3, 5 ppm; week 4, 10 ppm;week 5, 10 ppm; and week 6, 16.67 ppm. Variable readings only occurredon week 6, with 2 readings of 20 ppm and 1 reading of 10 ppm in eachroom of the barn.

FIG. 4B shows a multidimensional preference analysis of all focal birdtibia (n=70) measures 1-3: bone breaking strength (BBS), bird weight,tibia weight, bone mineral content (BMC), and bone mineral density(BMD). Abbreviations: C: control bird; and L: laser-enriched bird.Symbols denote individual focal birds. 1. Right tibia were collectedfrom 70 focal birds on d42, weighed, DXA scanned for BMC and BMD, andfractured using an Instron 3367 Test Machine compression method for bonebreaking strength; 2. The cosine between 2 variables indicates thecorrelation between the variables, the length of the arrows reflect thevariance of the original variables. This is a 2-dimensionalapproximation of the dimensions; 3. Original variables have beentransformed into new variables (Component 1 and 2) that account for mostof the variance.

Means from the ammonia monitor were compared using a simple frequencyand chi square distribution with enrichment treatment as a fixed effect.Treatment effect was not significant (P=0.112). In the control room ofthe barn, 60% of readings were 0 ppm, 20% were 3 ppm, and 20% were 8ppm. In the enriched room, 60% of readings were 0 ppm, 20% were 3 ppm,and 20% were 4 ppm. Thus, according to the more accurate GasAlertammonia monitor, the control room peaked at 8 ppm and the enriched roomnever surpassed 4 ppm at bird height.

4. DISCUSSION

At the commercial level, improved FCR is arguably the most valuedproduction trait as it translates to greater weight gain from the sameor lesser amount of feed, a cost savings in production, and thusimproved sustainability (Stenholm and Waggoner, 1991). Reducing FCR by17 points could equal to more than a 5% decrease in feed costs(Emmerson, 1997), which account for >70% of the costs of broilerproduction (Banerjee, 1992). The laser enrichment device successfullydecreased FCR by 18 points in the finisher period of our study vs.control. The increased weight gain of 0.24 kg/bird overall could betranslated to between $0.71 and $1.39 more saleable product/bird, usingcurrent breast meat prices as an example (USDA, 2019). Improved feedconversion may be attributed to decreased maintenance requirements, ormore energy partitioned towards growth (Urdaneta-Rincon and Leeson,2002).

Laser-enriched birds showed significantly increased physical movementduring laser periods (Meyer et al., unpublished data). Increasedphysical activity has been reported to reduce leg disorder parameters inbroilers (Prayitno et al., 1997; Reiter and Bessei, 2009) and layinghens (Shipov et al., 2010), but has also been associated with worse feedconversion (Akbar et al., 1985), or no change in weight gain or FCR(Prayitno et al., 1997; Reiter and Bessei, 2009; Ruiz-Feria et al.,2014). Indeed, feed conversion in chickens may have a behavioralcomponent, as was suggested in laying hen genetics research by Fairfulland Gowe (1979), but whether this effect may be positive or negativebased on exercise has remained unclear. Similar results to ours wereseen by Sorensen et al. (2000) where broilers raised at a lower stockingdensity showed both increased weight gains and improved walking ability.It was hypothesized by Lewis and Hurnik (1990) that there is likely a“locomotory-neutral zone or comfortable upper limit” in broilermovement, meaning that there is an ideal activity level somewherebetween the bare minimum distance traveled to access necessary resourcesand overexertion.

Researchers have successfully forced broilers out of the bare minimumrange of movement by increasing distance or introducing barriers betweenfeeders and waterers without compromising performance (Ventura et al.,2012; Ruiz-Feria et al., 2014), but other, non-resource-based methodshave been less successful. For example, Bizeray et al. (2002) testedwheat scattered on the pen floor and colored, moving spot-lights butconcluded that “forcing animals to exercise more . . . was moreeffective for increasing physical activity than was attempting tostimulate foraging activities.” Shields et al. (2005) hypothesized thatbroiler exercise would increase, and leg lameness would decrease, whenprovided sand bedding, but they were unable to support this as birdsrested and displayed more inactive behavior on the sand.

Thus, it appears that the success of the laser device and methodaccording to the present invention in motivating broiler physicalactivity, while simultaneously improving FCR and ADG, is among the firstto accomplish this goal. Further, we may speculate that the 4-min laserperiods induced a suitable amount of physical activity withoutincreasing maintenance requirements, hence sacrificing FCR or incurringnegative changes to footpad quality, but different lengths of time wouldneed to be tested to validate if this is the most ideal duration. Theincreased FI observed in laser-enriched pens may be attributed to thelaser motivating the broilers to move, thus driving them towards thefeeders. It has been established by Yngvesson et al. (2017) that whenresting broilers are disturbed by their conspecifics (a commonoccurrence), they get up and walk away. We hypothesize that a similareffect was driven by laser-enriched birds, who were physically active ata level considerably greater than control birds at the same time duringlaser periods, triggering other birds in the pen to move and ultimatelymove towards the feeders, much like the presence of humans walking acommercial barn motivates broilers to rise and head towards feed.Yngvesson et al. did not record feeding behavior post-disturbance forcomparison, but this hypothesis is supported by our finding that 71% oflaser-enriched focal birds were at the feeder at least once eitherduring or within 5 min following laser periods (Meyer et al, unpublisheddata).

It is thought that most skeletal support is established in broiler birdsby day 18, following “intensive bone formation to provide rapidmineralization.” However, bone porosity or density changes more slowlyover time to support increasing bird weight (Williams et al., 2000).Further, bone strength and mass are increased with activity (Rath etal., 2000), and load-bearing bones need to develop bearing weight, orthey will immediately fail to do so when given the opportunity (Lanyon,1993). Thus, we hypothesized that the increased movement, activity, andgrowth seen in laser-enriched birds may have been reflected in improvedtibia quality measures (Meyer et al., unpublished data). DXA scanninghas been used successfully in broilers to measure BMD and BMC (Swennenet al., 2004; Shim et al., 2012; Castro et al., 2019), and bone breakingstrength has been used to detect treatment differences as well (Rowlandand Harms, 1970; McDevitt et al., 2006; Shim et al., 2012). Bone mineraldensity is believed to be reflective of mineral content (Rath et al.,2000); our highly correlated (r=0.857) BMD and BMC values agree withthis. Further, BMD and BMC of the tibia obtained from DXA scanning werewithin normal range, similar to values seen in broiler tibia by Shim etal. (2012).

Body weight, tibia weight, BMD, and BMC collectively explain 71.25% ofthe total experimental differences seen in these variables (FIG. 4B).Body weight and tibia weight positively influence overall bone measuresand tightly cluster, while BMC and BMD cluster with an overall weaknegative influence on the collective bone-related outcomes. Although BMDis commonly used as an indicator of bone strength, as bonemineralization is believed to provide compression strength (Rath et al.,2000), our data indicate a weak negative correlation between BMD and BMCof tibia with bone breaking strength (FIG. 4B), an outcome that was notexpected based on previous work in poultry (Leterrier and Nys, 1992).However, work done in humans (Divittorio et al., 2006) has indicatedthat in-creases in bone density are not consistently correlated withdecreased occurrence of fractures, and work in non-human primates (Vahleet al., 2015) stated that BMD is not always indicative of bone will failin “repetitive loading, as in a stress fracture, or when subjected tohigh impacts.”

Our bone breaking methods using compression and a constant rate of loadwould have reflected this repetitive loading and may contribute to thelack of correlation seen between these bone quality measures. Furtherwork is necessary to validate this unexpected, negative correlation. Itis important to note that BMD, BMC, and breaking strength were eachnumerically higher in laser-enriched birds. These outcomes havepreviously been seen by Shim et al. (2012) in fast-growing broilerscompared to slow-growing broilers, but when analyzed in terms of bodyweight of the birds, the slow-growing birds ultimately had better bonequality. However, in our study the body weight of birds was weaklynegatively correlated with bone breaking strength (r=−0.325), indicatingthat this measure was not sim-ply reflective of tibia weight or birdweight, but rather a possible true numerical increase of bone quality inthe enriched birds.

Commercially, contact dermatitis including breast blisters and footpaddermatitis necessitates downgrading of 15 to 30% of broiler carcasses/wk(Greene et al., 1985). Breast conditions range from “mild” brownishcolored scabs to “severe” exudate and litter filled ulcers that areaggravated because broilers rest 60% of their body weight on the keelwhile lying (Nielsen, 2004). Footpad dermatitis is a similar condition,but on the bottom of broiler feet and toes, with symptoms ofinflammation and necrotic lesions. This is an obvious animal welfareconcern, but also represents a considerable economic loss to theindustry, where paws are “the third most important economic part of thechicken behind the breast and wings . . . accounting for approximately$280 million a year” (Shepherd and Fairchild, 2010). However, in ourclean research environment, neither of these conditions occurred. Otherresearchers have assessed these on commercial broilers at theslaughter-house to gather a true representation of the issue (Allain etal., 2009), and considering that our birds were housed on fresh pineshavings with a relatively lower stocking density and number of birdsthan a commercial broiler house (0.24 m²/bird recommended by the NCC;0.33 m²/bird provided), we were not expecting a high occurrence in ourflock. However, we were able to successfully show that the enrichmentdevice did not negatively influence the birds' health by worseningbreast or feet condition compared to the control.

Tied in with breast blisters and footpad dermatitis are air and litterquality. These conditions may be caused by ammonia, originating fromurea in the litter compounded by mixing with leaked water from drinkers,causing a chemical burn effect. Haslam et al. (2006) showed thatpercentage of birds with footpad concerns was correlated with ammoniaconcentrations in the house and litter moisture, although they did notfind this association with breast burns. In the cur-rent study, ammonialevels were low, peaking at 8 and 4 ppm on the control and enrichedrooms of the barn, respectively, using the GasAlert monitor. This iswell within the acceptable range of up to 25 ppm accepted by the NCCaudit. Likewise, litter remained dry and friable throughout 6 wk in bothrooms of the house. These outcomes indicate that the larger, more activelaser-enriched birds were not generating more moisture in the litterfrom increased waste or stirring up greater quantities of ammonia overthe course of the experiment.

Regarding impact of the laser on bird welfare, data from this study havethus far provided no evidence that animal welfare was negativelyimpacted by laser enrichment. There was not an increase in lameness,dermatitis, or mortality, nor did we see a decrease in body weight,tibia quality, or environmental conditions due to laser treatment. Inthe behavior companion paper (Meyer et al., unpublished data), theHuman-Approach Paradigm was utilized as a measure of fearfulness.Results showed that a greater number of laser-enriched birds were closerto the unfamiliar human in the pen during week 6 of the trial than thecontrol birds; hence, an increased fear response was not observed.Future work in this area should include taking physiological stressmeasures, such as serum or feather corticosterone, to determine if laserenrichment is causing a stress response in broilers. However, it hasbeen shown that broilers are interested in exploring novel objects(Newberry, 1999), and have a propensity to peck at small objects (Hogan,1973), so although it is certainly possible that in some cases birds mayhave been moving away from or unduly stressed by the lasers, thus farour data indicate they were not negatively impacted and were ratherinterested in the novel nature and small size of the laser dots.

In summary, these data have provided a strong indication of positiveperformance effects related to this novel environmental enrichmentdevice. Furthermore, the environmental enrichment device did not resultin any unintended negative consequences on the birds' tibia quality,breast and feet condition, or living environment. This unique deviceimproved gains and feed conversion compared to the control, with peakperformance results seen in the crucial grower and finisher periods.Following future validation in research and in a commercial setting,this enrichment option may be effective for producer implementation. Thedevice does not come into contact with birds, there-fore reducing thepotential for disease vectors (as in perches/straw bales/tiles) and canbe used across multiple flocks. Further work is needed to refine thedevice and performance outcomes, and this work also needs to be extendedto commercial conditions.

5. SUPPLEMENTARY DATA

Supplementary data are available at Poultry Science online atdoi.org/10.3382/ps/pez417 (which is incorporated by reference herein).

6. REFERENCES

The following publications are referenced in the foregoing descriptionof Section D and provide background information.

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E. Specific Example 2 (Relative to Broiler Chickens and IncreasedPhysical Activity)

For further understanding of the invention and its aspects, below is astill further application of concepts according to the invention to aparticular species of poultry, namely broilers, which, as is well knownby those skilled in this technical art, are chicken bred and raisespecifically for meat production.

Exemplary embodiments of apparatus, systems, and methods according tothe invention are described in detail. Proof of concept evidence is alsoincluded. Again, however, this is a non-limiting example of theinvention. This will help the reader further understand objects of theinvention by the details of this specific example and context.

1. INTRODUCTION

Today's commercial broiler is up to 5 times heavier than its 1950'spredecessor at the same age due to genetic selection for 3-fold improvedfeed efficiency and a 300% increased growth rate, resulting in a birdreaching market weight in as little as 4-6 wk (Havenstein, et al., 2003;Knowles, et al., 2008, Zuidhof, et al., 2014). However, this selectionfor increased growth rate has contributed to up to 30% of moderncommercial broilers suffering from leg lameness or and reduced abilityto move (Knowles, et al., 2008; Bassler, et al., 2013). Increased ageand lameness both contribute to decreased time standing or walking.Sound birds spend around 76% of their time sitting or lying down, whilelame birds spend up to 86% of their daily time budget inactive. Atharvest weight (approximately 2 kg), healthy birds are reported to spendonly 3.3% of their day walking, versus 1.5% in lame birds (Weeks, etal., 2000). Weeks and others hypothesized that fast-growing, more feedefficient broilers are inherently more inactive. Inactivity increaseslitter contact and could result in a higher occurrence of breastblisters and contact dermatitis (Weeks, et al., 2000; Bassler, et al.,2013; NUAs, et al., 2018), which are likely painful conditions caused byurea in the litter generating ammonia, creating chemical burns (Haslam,et al., 2007). Hence, past broiler research has studied physicalactivity and methods to increase active behavior.

Reiter and Bessei (2009) used treadmill training to force broilers toexercise for sessions lasting 20 min or 100 m wk 1-6 and saw improvedlocomotion. In an additional test from the same study, when distance wasgradually increased over d0-5 from 2 to 12 m between feed and water,locomotion was increased threefold compared to the control, whereresources remained 2 m apart throughout. Similar methods have beensuccessfully used to encourage broilers above the minimum range ofmovement by increasing distance or introducing barriers between feedersand waterers without compromising performance (Ventura, et al., 2012;Ruiz-Feria, et al., 2014), but other, non-resource-based methods havebeen less successful.

Prayitno and others (1997) used ambient red light to stimulate activityin broilers but saw birds with a mean final body weight 47-79±12.4 glighter than birds in a blue light treatment. However, broilers in theblue light were significantly less active. Bizeray and colleagues(2002a) tested different forms of enrichment by scattering wheat on thefloor of the pen in one treatment, colored, moving spotlights inanother, and barriers between feed and water in a third, but concludedthat “forcing animals to exercise more . . . was more effective forincreasing physical activity than was attempting to stimulate foragingactivities”. Shields and others (2005) hypothesized that broilerexercise would increase, and leg lameness would decrease when providedsand bedding, however, birds rested and displayed more inactive behavioron the sand. Ventura et al. (2012) implemented barrier perches asenvironmental enrichment but saw no increase in walking. Straw bales asa form of “freedom food” were successful in increasing broiler activity,but performance or walking ability data were not reported. Performancemay have been negatively impacted in the straw bale treatment due toincreased fiber in the gut, indicated by the increased drinking behavior(Kells, et al., 2001).

The National Chicken Council (NCC) guidelines for broilers (2017) haverecognized leg lameness as a welfare concern and recommend gait scoring100 birds/flock to evaluate leg health within 1 wk of slaughter usingthe U.S. Gait Scoring technique. This is a three-point scoring systemthat has been validated in commercial broiler flocks for highreliability compared to a 6-point system (Webster, et al., 2008).However, gait-scoring individual broilers in a research pen, rather thana commercial barn, may prove problematic due to limited space, feeders,and waterers in a confined area. Lameness hurts the industryeconomically, necessitating up to 2% culls in a $30 billion industry(USDA, 2017; Dunkley, 2018), and there is also considerable evidencethat leg lameness is painful for the broiler. Birds with leg lamenesseat more analgesic-containing feed than healthy birds, and birds fed ananalgesic diet showed improved speed of walking, indicating relief frompain and discomfort caused by leg abnormalities (McGeown, et al., 1999;Danbury, et al., 2000).

Environmental enrichment has shown the ability to reduce fearfulness inbroilers (Altan, et al., 2013). The Human-Approach Paradigm (HAP) is avalidated measure of fearfulness in pigs that uses an unfamiliar humanin the pen as a stimulus (Weimer, et al., 2014). The HAP has not beenstudied thus far in broiler chickens but is a potentially useful measurethat takes into account both the movement and the orientation of theanimal in relation to the human. The previously mentioned study byBizeray et al. (2002a) is the only research that has measured theeffects of environmental enrichment in the form of moving lightsprojected onto broiler pen floors. The authors implemented red, blue,green, and yellow spotlights but saw no change in broiler physicalactivity, and thus concluded that that the spotlights were too large andmoved too quickly for broilers to follow. Moving light/visual enrichmentsuccessful in motivating broiler activity and improving well-beingoutcomes is absent in the literature. Furthermore, birds are visualfeeders and prefer the color red (Ham and Osorio, 2007). Hence, thepresent work measured the effects of slowly moving, small particle-sizedred laser dots projected onto broiler pen floors throughout the rearingperiod as a unique enrichment option. The objectives of this work wereto stimulate broilers visually using a novel form of environmentalenrichment to motivate physical movement, hence increasing walkingdistance and improving walking ability.

2. MATERIALS AND METHODS

All live bird procedures were approved by the Iowa State UniversityInstitutional Animal Care and Use Committee.

a. Animals

1260 straight-run Ross 308 broiler chicks (day of hatch; BW 47.38±0.14g) were obtained from a commercial hatchery and transported to thePoultry Research and Teaching Unit at Iowa State University(International Poultry Breeders Hatchery, Bancroft, Iowa) for a 6-wkgrow-out experiment in floor pens. 1200 were randomly assigned totreatments and the remainder were culled following standard operatingprocedures of the farm. Seventy birds were randomly assigned uponarrival as focal birds (n=5 birds/pen in 14 camera pens), identifiedwith wing-bands, and marked with unique animal-safe food coloring (red,blue, green, purple, and black; Wilton, Woodridge, Ill.). Food coloringwas applied to a cotton ball, rubbed on the back of the chick's head andneck, and reapplied on an as-needed basis throughout the 6-wk trial.

b. Housing and Feeding

Birds were housed in 40 1.22 by 2.44 m pens of 30 across 2 rooms in thebarn. One room contained 20 LASER pens (exposed to enrichment device),and the other contained 20 control pens, with an anteroom separating the2 rooms so no crossover of enrichment device was possible; environmentalconditions and management were kept the same across rooms. Approximately10 cm deep fresh wood shavings provided bedding over the solid concretefloor, and PVC pipe dividers with mesh walls (1.22 m height) separatedpens. High and low temperatures and humidity were monitored daily in theLASER and control rooms. Average temperatures are listed from thestarter, grower, and finisher periods respectively from the LASER roomof the barn: 85.47° F., 77.39° F., and 71.71° F., and the control room:85.53° F., 77.46° F., and 71.5° F. Average relative humidity is listedfrom the starter, grower, and finisher periods respectively from theLASER room: 23.86%, 27.21%, and 33.93%, and the control room of thebarn: 19.89%, 23.93%, 27.75%.

Birds were gradually adjusted from 24 h light on d0, defined as day ofarrival and placement, (30-40 lux) to 20 h light (20-30 lux) from d8-42.Chicks were brooded with 2-heat lamps/pen (22.9 cm reflectors withporcelain socket) using 125-watt heat bulbs (Sylvania, Wilmington,Mass.) for the first wk. Birds were fed an ad libitum diet formulatedfor Ross 308 commercial recommendations out of a hanging chicken feeder(BRHF151, Brower Equipment, Houghton, Iowa) gradually raised toaccommodate bird height. Water was provided ad libitum from a hangingnipple water line (8 nipples/pen). Mortality throughout the trial was3.5% in control birds and 3.33% in LASER birds.

c. Laser Enrichment Device

Ten novel laser enrichment devices designed and built specifically forthis research were affixed over 20 pens in 1 room of the barn. Eachdevice was designed and calibrated to cover 2 adjoining pens. Theenrichment device consisted of 2 independent red 650 nm lasers containedwithin a 20.5 by 20.5 cm metal box with a glass bottom mounted on acustom-designed structure made of 3 wooden beams (2.4 m height) raisedabove the pens. The lasers projected in a random pattern at a range of7.6-30.5 cm/second onto the pen floor for 4-min “laser periods”: 05:30to 05:34, 11:30 to 11:34, 17:30 to 17:34, and 23:30 to 23:34 daily forthe entirety of the trial.

d. Video Camera Set-Up and Training

Seventy focal birds (n=5/pen) were randomly assigned to 14 randomlyselected pens (7 LASER, 7 control) equipped with 1 Sony HDR-CX440Handycam (Sony Corp. of America, New York, N.Y.) each. Cameras wereaffixed above each pen using brackets adjusted to capture the entirepen. Filming occurred in real-time (30 fps) for the first 10 days of thetrial (d0-9) and once weekly for the remainder. Video observers weretrained by an individual with previous animal behavior observationexperience to 90% agreeability using the 4-min laser period video clipsfrom any day recorded (d0-9, 16, 23, 30, and 37). All clips recordedwere analyzed for the entirety of the enrichment period in LASER andcontrol pens. Observers were not blinded to treatment; either the lasersor the supporting structure were visible in the videos/images.

e. Broiler Bird Home Pen Behavior

Trained observers watched the red-colored focal bird in eachvideo-recorded pen (n=14) during 4-min laser periods and categorizedbird behavior continuously throughout the clips using a pre-determinedbehavior ethogram (Table E1) on d0-9, 16, 23, 30, and 37. Frequency andduration (s) of each behavior were recorded; duration was then convertedto percent of time spent on each behavior per 4-min period.

TABLE E1 Broiler bird home pen behavior ethogram; focal bird behaviorwas measured continuously during 4-min laser periods, 4 times daily at05:30, 11:30, 17:30, and 23:30 for d0-9, 16, 23, 30, and 37 Measure¹Defined Active Bird legs were in a continuous forward motion (walking orrunning). Inactive Bird stood in one place or rested its abdomen on thelitter, head rested or raised while any part of its body was or was notin contact with another bird. At feeder Bird head over feeder circle,bird in feeder or bird stood on feeder tray. At drinker Bird stoodbeneath drinker line. Other Dust-bathed, preened (head/beak twistedaround in contact with feathers), or any behavior not otherwiseidentified. Out of view² Bird was obstructed or not observed due tobeing under the heat lamp or inside the feeder and could not be seen.¹All behaviors were collected as duration, defined as length of timebehavior was exhibited in seconds ²Behaviors categorized as “Out ofview” were so infrequent that the data could not be analyzed; relaxedconvergence criteria was attempted to 10⁻⁴

f. Latency to Feed

Latency to feed following laser turn-off was measured only in LASER penson d0-9, 16, 23, 30, and 37 due to necessity of laser turn-off and todetermine if birds exposed to laser enrichment went to the feeder afterthe conclusion of laser exposure. At feeder behavior during laserperiods was collected in both LASER and control pens as directcomparative measure. A student observer watched laser period video fromthe 7 LASER pens and identified the red-colored focal bird. At the endof the 4-min period, when the laser dots disappeared, the observerstarted a timer. The timer was stopped when the focal bird exhibited “atfeeder behavior” (Table E1) or when 5 mins had passed without the birdfeeding. Latency to feed was recorded in seconds. Following datacollection, latency to feed measures were categorized into 4 mutuallyexclusive categories, including: A) at feeder during laser period only(obtained from broiler home pen behavior data), B) at feeder when laserturned off, C) went to feeder<5 min following laser turn off, and D)never went to feeder.

g. Walking Distance

The distance walked by the blue-colored focal bird in eachvideo-recorded pen (n=14) was measured over the 4-min laser periods(d0-9, 16, 23, 30, and 37). The observer taped a clear sheet protectorover the computer screen and watched each min individually. At thebeginning of each min, video was stopped, and the observer drew a lineat the bird's beak. Video was resumed, and if the bird moved the videowas paused again and a line was drawn at the new position of the beakwhere the bird stopped. This was repeated each min. Next, the observerused a ruler to draw a line connecting each stopping mark. After drawingthe interconnecting line, the observer opened a pen template image inAdobe Photoshop (Adobe Systems Inc, San Jose, Calif.).

The observer then used a known length within the pen (58.4 cm between 2segments of the water line, measured on-farm) to standardize the customruler tool on Photoshop, measured in pixels (58.4 cm=approximately 194pixels). The tool would then equate x number of pixels to centimeters.The observer placed the clear sheet protector over the template imageand used the custom ruler tool to measure the interconnecting linesdrawn from video. This was repeated for each individual min and then asum of all line measurements, or the total distance walked each period,was calculated.

h. Walking Lameness

All focal birds (n=70) were removed from their home pens once weekly andassessed for lameness. Two researchers conducted the lameness test, with1 researcher assigning scores. Birds were placed on a custom-designedplywood runway 1.80 m long and 0.46 m wide, with 0.30 m tall walls onall sides. The runway had 0.15 m start and finish sections, a 1.5 mwalking space, and delineations marking every 0.30 m and 2.5 cm. Birdswere placed on the runway starting section. Birds either walked 1.5 mindependently or were encouraged to walk by (1) a researcher slowlymoving their hand back and forth directly behind the bird (2) aresearcher gently tapping the bird on the vent region with a gloved handor (3) a researcher both waving behind and gently tapping the bird witha ping-pong paddle. Individual birds were considered to have completedthe task when both feet had crossed into the finish section. Scores wereassigned using a 0-2 scale adapted from NCC guidelines where 0 indicatedthe ability to walk 1.5 m with no signs of lameness, 1 indicated theability to walk 1.5 m but showed unevenness in steps or sat down atleast once, and 2 indicated a bird that could not walk 1.5 m.

i. Human-Approach Paradigm

The Human-approach paradigm (HAP) was completed once during wk 1 andonce during wk 6 on all birds (n=1200) beginning at 09:00; pen order waskept the same each wk (n=40 pens). The barn was emptied of personnelapart from 2 researchers carrying out the HAP. Prior to the HAP, theresearchers determined optimal bracket angle and camera location foreach pen, so that 1 image captured an entire pen. Colored tapeidentified bracket location; locations ranged between 47.75-59.00 cmmeasuring out from the central PVC pipe. The HAP image was taken with ahand-held camera (Pentax Optio W90, Pentax Imaging Company, Golden,Colo.). The camera's focal length was 28 m with a 12.1-megapixelresolution.

Methods were based on swine nursery work completed by Weimer, et al(2014). Briefly, researcher A was defined as an unfamiliar human in thepen and researcher B placed the camera/bracket and took the image.Researcher A wore different colored coveralls than the rest of theresearch and farm crew, but the same boot covers. The researchersapproached each pen quietly and recorded the number of birds per pen.Researcher B positioned the bracket on the pen's side in thepre-determined location and then Researcher A stepped into the oppositeside of the pen with a stopwatch in their right hand. Researcher A tookone step towards the center of the pen opposite Researcher B andcrouched facing the camera with their body angled towards the birds andboth arms held close to the body. Once in position, Researcher A beganthe stopwatch, avoiding looking at the birds for 15 s. After 15 s,Researcher A stopped the watch and looked up at the birds. Researcher Btook an image at the precise moment Researcher A looked up.

One student observer, trained using the same methods as video observersbut with wk 1 HAP images, reviewed the images. Within each digital imageof individual pens, broilers were classified into 2 categories:interacting or not interacting. Interacting was defined as any bird inphysical contact with or orientated directly towards the unfamiliarhuman. Birds classified as not interacting were further categorized into3 mutually exclusive behaviors: feeder, drinker, or other (Table E2).Further, the pen images were split into fourths by tracing over PVC pipesupports every 0.6 m in the pen with a clear sheet and a marker. Thenumber of birds present in each quadrant of the pen was counted, withquadrant 1 containing the unfamiliar human (FIG. 5).

FIG. 5 relates to: Digital Human-Approach Paradigm (HAP) wk 1 image usedfor evaluation¹, where numbered circles relate to: ¹Bird 1: Interacting;Bird 2: Not interacting; Bird 3: At drinker; Bird 4: At feeder; Bird 5:Other.

TABLE E2 Broiler behavior classification using a digital image analysisupon conclusion of human-approach paradigm (HAP¹). Birds were firstcategorized as interacting or not interacting, then not interactingbirds were separated into 3 mutually exclusive categories²: feeder,drinker, or other. Measure Definition Classification at 15 s usingdigital image evaluation Interacting Using a ruler and a clear sheetprotector taped to the screen, a line was drawn from the midpoint of thebird's head to the pen edge. If the line intersected with researcher A,or if any part of the bird was physically contacting researcher A, thebird was classifed as interacting. Not interacting Birds not exhibitingthe above two behavioral classifications. Further classification of notinteracting using digital image evaluation Feeder Bird head over feedercircle, bird in feeder or bird stood on feeder tray. Drinker Bird stoodbeneath drinker line. Other Laying (rested its abdomen on the litter,head rested or raised³), preening (dust bathed or head/beak twistedaround in contact with feathers), wings stretched out, piling (group ofthree or more birds pressed against each other and/or on top of eachother, all bird heads facing away from the human in the pen and notperforming any other discernible behavior⁴), or not visible. ¹HAP wascarried out on all pens once on wk 1 and once on wk 6. An unfamiliarhuman entered the pen and after 15 s, a photograph was taken to measurethe birds' response ²Ethogram adapted from Weimer et al. 2014³Kristensen, et al., 2007 ⁴Campbell, et al., 2016

j. Statistical Analysis

In this experimental design, individual control pens (n=20) wereconsidered experimental units, but LASER pens were analyzed as a groupof 2 pens with 1 shared laser device (n=10). All data were analyzedusing SAS software version 9.4 (SAS Institute Inc., 2016, Carey, N.C.).PROC UNIVARIATE was used to assess the distribution of data prior toanalysis. Home pen behavior, walking distance, and HAP data were allabnormally distributed (Poisson distribution), thus were analyzed usingPROC GLIMMIX. GLIMMIX fits models to data with non-constant variability,correlations, or that are not normally distributed. Home pen behaviorand walking distance data were analyzed by day (d0-8) and by wk (d2, 9,16, 23, 30, and 37), utilizing all laser periods within each day. Eachmodel (behavior, walking distance, and HAP) included the fixed effect oftreatment (enrichment versus control), wk or day, and the treatment bywk or day interaction, with the random effect of pen (or enriched pairof pens) within treatment, as birds were randomly assigned to pens.

Latency to feed and walking lameness categorical data were analyzedusing PROC FREQUENCY and CHI SQUARE. The distribution of latency to feeddata were observed by day and wk; only LASER focal birds were analyzed,thus treatment was not included in the model. Lameness scoredistributions were observed by treatment and the association of score totreatment. For all measures, a value of P≤0.05 was consideredsignificant and differences between means were detected using PDIFF.

3. RESULTS

a. Broiler Home Pen Behavior

The day×treatment interaction was significant for all behaviorsmeasured: active, inactive, time at feeder, drinker, and other (P<0.01).Birds out of view occurred so infrequently that data could not beanalyzed: the frequency of out of view behavior on d0-8, respectively,were 0.11±0.31; 0.36±1.08; 0.27±0.59; 0.29±0.53; 0.55±1.01; 0.46±0.77;0.27±0.66; 0.1±0.36; and 0.05±0.21. Out of view frequency for wk 1-6,respectively, were 0.27±0.59; 0.05±0.21; 0, 0.04 35 0.19; 0.05±0.23; and0.02±0.13. LASER birds spent more time active (walking or running) ond0, 1, 3, 4, 5, 7, and 8 compared to the control (P<0.05, FIG. 6A). Thegreatest increase in active behavior was observed on d7, where LASERbirds moved 17.4±1.6% more, equal to a 253% increase, than their controlcounterparts. LASER birds were less inactive than the control on d2, 3,4, 5, 6, and 8, with a peak 29.3±3.3% decrease on d2 (P≤0.05, FIG. 6B).

FIGS. 6A-D relate to: Ross 308 broiler home pen behavior results offocal bird during 4-min laser periods: day×treatment LSMeans (±SEM)¹percent of time spent: (A) active; (B) inactive; (C) at feeder²; and (D)at drinker; with day and treatment as main effects, d0-8³. ¹Valueslacking a common superscript are significantly different (P≤0.05)²Atfeeder convergence criteria relaxed to 10⁻⁶ ³Individual P-values fromd0-8, respectively: A)<0.0001, <0.0001, 0.5052, <0.0001, <0.0001,0.0172, 0.5317, <0.0001, <0.0001; B) 0.6692, 0.3802, <0.0001, 0.0042,<0.0001, 0.0157, 0.001, 0.5467, 0.0041; C) 0.0141, <0.0001, 0.0276,0.0036, 0.0918, 0.0022, 0.5056, 0.0946, 0.002; and D) 0.0002, <0.0001,0.0023, 0.0702, 0.5939, 0.041, <0.0001, <0.0001, 0.0176.

LASER birds spent more time at feeder on d0, 1, 2, 5, 8 than the control(P≤0.05, FIG. 6C). On d5, LASER birds were at the feeder 10.2±2.4% morethan control birds, equal to an 83.7% increase. Control birds spent agreater amount of time at the feeder on d3. Control birds spent agreater percent of time at drinker on d0, 1, 5, 7, and 8, but LASERbirds spent more time at drinker on d2 and 6 (P≤0.05, FIG. 6D). Controlbirds displayed a greater percent of “other” behaviors on d2, 5, and 8,while LASER birds showed a greater percent of this behavior on d4(P≤0.05). Other behavior did not contribute heavily to focal bird timebudget, with a maximum percent of 4.01±0.59% in LASER birds (d3) and4.02±0.63% in control birds (d2). The estimated mean time budgets oflaser-enriched birds over d0-8 were: 14.1±1.29% active, 47.09±2.83%inactive, 14.05±1.87% at feeder, 6.62±1.13% at drinker, and 1.37±0.19%0.60% active, 59.8±3.57% inactive, 9.8±1.32% at feeder, 10.17±1.69% atdrinker, and 1.66±0.23% engaged in other behavior.

When analyzing one d/wk (Thursday of each week) the wk×treatmentinteraction was significant in all behavior categories (P≤0.01). LASERbirds spent a greater percent of their time active than control birds onwk 2, 12.2±2.8% greater (114% increase); wk 3, 8.2±1.6% greater (157%increase); wk 4, 2.5±0.74% greater (90% increase); and wk 5, 2.9±0.87%greater (82% increase, P≤0.05, FIG. 7A). LASER birds spent less timeinactive than the control on wk 1 and 5 (P<0.05, FIG. 7B). Time atfeeder was increased in wk 1 by 8.2±3.0%, and in wk 5 by 17.8±3.0%, a247% increase, in LASER birds (P≤0.05, FIG. 7C). Time spent at drinkerwas increased in LASER birds by 6.5±1.7% in wk 1 and 7.2±1.43% on wk 6and was 7.9±1.4% higher in control birds on wk 3 (P≤0.05, FIG. 7D).Other behavior showed no differences by treatment within individualweeks. The estimated mean time budgets of laser-enriched birds over wk1-6 were: 7.49±1.2% active, 53.77±4.07% inactive, 17.19±3.17% at feeder,6.49±1.18% at drinker, and 0.83±0.45% engaged in other behavior. Theestimated mean time budgets of control birds over wk 1-6 were:4.55±0.73% active, 62.64±4.73% inactive, 14.75±2.72% at feeder,6.75±1.22% at drinker, and 0.77±0.42% engaged in other behavior.

FIGS. 7A-D relate to: Ross 308 broiler home pen behavior results offocal bird during 4-min laser periods: week by treatment LSMeans (±SEM)¹percent of time spent: (A) active; (B) inactive; (C) at feeder; and (D)at drinker; with day and treatment as main effects, wk 1-6² ¹Valueslacking a common superscript are significantly different(P≤0.05)²Individual P-values from wk 1-6, respectively: A) 0.7414,0.0013, 0.0001, 0.014, 0.0182, 0.931; B)<0.0001, 0.6187, 0.2516, 0.492,0.0008, 0.4202; C) 0.049, 0.5083, 0.0867, 0.4501, <0.0001, 0.9323; andD) 0.006, 0.0519, <0.0001, 0.939, 0.3656, 0.0002.

b. Latency to Feed

Latency to feed categorical distributions were affected by day (d0-8,P<0.01) and by wk (wk 1-6, P=0.03). Over days 0-8, 15.34±0.40% of LASERfocal birds were at the feeder during laser periods (but not in 5 minsfollowing laser turning off), 33.33±0.73% went to the feeder in <5 minsfollowing laser turn off, 22.22±0.48% were already at the feeder whenlaser periods ended, and 29.1±0.77% never went to the feeder during orin 5 mins following laser period. Individual daily proportions arepresented in FIG. 8A. Over wk 1-6, 5.44±0.37% of birds were at thefeeder during laser periods only, 28.57±0.76% went to feeder within 5min of laser turn off, 26.53±0.62% were already at the feeder when thelaser turned off, and 39.46±0.96% were never at the feeder. Weeklybreakdowns are presented in FIG. 8B.

FIGS. 8A-B relate to: Ross 308 broiler latency to feed of LASER focalbirds (n=7) by: (A) day, P=0.0014; and (B) week, P=0.03. Latency wasrecorded in seconds using video recordings from laser periods and for 5min following, then separated into 4 mutually exclusive categories

c. Walking Distance

For the first 9 days on trial, the day×treatment interaction wassignificant for each min individually and total distance walked(P≤0.01). LASER birds walked further in the first min on all days, withincreases up to 151.1±12.9 cm on d1, a 452% increase, and 107.5±11 cm ond7, greater than a 228% increase (P≤0.05, FIG. 9A). Likewise, LASERbirds walked more on all days during the second min, with an increase of236.3±30 cm, or a 237% increase, on d1 (P<0.05, FIG. 9B). During min 3,LASER birds walked more than control on d0, 1, 3, 4, 5, 6, and 8, with apeak increase of 139.8±21.2 cm, or a 270% increase, on d1 (P≤0.05, FIG.9C). In min 4, LASER birds walked greater distances on d0, 1, 2, 4, 5,6, 7, and 8, walking 150.9±21 cm (287%) more on d0 and 108.4±19.2 cm(183%) more on d1 (P≤0.05, FIG. 9D). Over the total 4-min laser periods,LASER focal birds walked a greater distance than control on all days,with increases reaching up to 646.45±64.6 cm, a 303% increase (d1,P≤0.05, FIG. 9E).

FIGS. 9A-E relate to: Mean walking distance (cm) of focal bird during4-min laser periods day×treatment LSMeans (±SEM)¹ during: (A) min 1; (B)min 2; (C) min 3; (D) min 4; and (E) total distance walked² (4 min),with day and treatment as main effects, d0-83 ¹Values lacking a commonsuperscript are significantly different (P≤0.05)² Total distanceconvergence criteria relaxed to 10⁻⁶ ³Individual P-values from d0-8,respectively: A)<0.0001, <0.0001, 0.0051, <0.0001, <0.0001, <0.0001,0.015, <0.0001, 0.0046; B) 0.0002, <0.0001, 0.0091, 0.0002, 0.0021,<0.0001, 0.0013, 0.0045, 0.0052; C)<0.0001, <0.0001, 0.6176, 0.0008,<0.0001, 0.0154, 0.0008, 0.4844, <0.0001; D)<0.0001, <0.0001, 0.0421,0.7928, <0.0001, 0.0008, 0.0141, 0.0247, 0.0119; and E) <0.0001,<0.0001, 0.0469, <0.0001, <0.0001, <0.0001, 0.0004, 0.0002, <0.0001.

Analyzed on a weekly basis (1 d/wk) the wk×treatment interaction wassignificant for each min individually and total distance walked(P≤0.01). During min 1 of laser periods LASER birds walked more on wk 1,2, 3, 4, and 5, with increases up to 88.6±15.7 cm (130%) on wk 2 and51.2±7 cm (215%) on wk 5 (P<0.05, FIG. 10A). During min 2, LASER focalbird walking distance was higher on wk 2 and 5 (P≤0.05, FIG. 10B). Inthe third min, the LASER birds walked more on wk 2, 3, 4, and 5, withincreases up to 80±19.7 cm (108%) on wk 2, P≤0.05, FIG. 10C. Within min4 LASER focal birds walked further than the control on wk 2 and 4, withan increase of 83.4±19.1 cm (176%) on wk 2 (P≤0.05, FIG. 10D). Totaldistance walked during 4-min laser periods was increased on wk 2-5 inLASER pens, with the greatest increase of 367.5±61.9 cm, or 150%, on wk2 (P≤0.05, FIG. 10E).

FIGS. 10A-E relate to: Mean walking distance (cm) of focal bird during4-min laser periods: week by treatment LSMeans (±SEM)¹ during: A) min 1;B) min 2²; C) min 3; D) min 4; and E) total distance walked; with weekand treatment as main effects, wk 1-63 ¹Values lacking a commonsuperscript are significantly different (P≤0.05)² Min 2 convergencecriteria relaxed to 10⁻⁵ ³Individual P-values from wk 1-6, respectively:A) 0.0125, <0.0001, 0.0426, <0.0001, <0.0001, 0.1839; B) 0.0977,<0.0001, 0.3027, 0.0662, <0.0001, 0.0833; C) 0.5823, 0.003, 0.0012,0.0008, 0.0057, 0.4316; D) 0.2079, 0.0009, 0.1009, <0.0001, 0.2708,0.2253; and E) 0.1363, <0.0001, 0.0165, <0.0001, <0.0001, 0.9931.

d. Walking Lameness

Out of the 420 lameness measures taken (70 focal birds/wk for 6 wk), 400were scored 0 (no signs of lameness). There were 18 scores of 1 (birdshowed unevenness in steps or sat down at least once), and only 2 scoresof 2 (bird could not walk 1.5 m). In the control birds, 96.19% of scoreswere 0, 2.86% were scores of 1, and 0.95% of scores were 2. In the LASERbirds, 94.29% of scores were 0, 5.71% were scores of 1, and no scoreswere 2. The chi square relationship of score by treatment was notsignificant (P=0.13).

e. Human-Approach Paradigm

The wk×treatment interaction was significant for percent of birdsinteracting (P≤0.01). During wk 1, control birds interacted 2.2±0.73%more (P≤0.05), but on wk 6 there were no differences in birdsinteracting. Averaged over both treatments and wk 1 and 6, 95.59±2.19%of birds were not interacting and there was not a wk×treatmentinteraction (P=0.35, Table E3). In the not interacting furtherclassified behavior categories, there were 3.7±1.0% more control birdsat the drinker on wk 1 and 1.8±0.59% more LASER birds at the drinker onwk 6, with a wk×treatment interaction (P<0.01). There were nodifferences in percent of birds at the feeder wk 1 or 6 (wk×treatmentinteraction P=0.62), and no differences in birds exhibiting otherbehaviors on wk 1 or 6 (wk×treatment P=0.22, Table E3).

Regarding bird location in the home pen during the HAP, the main effectof wk was significant for all quadrants of the pen and the wk×treatmentinteraction was significant for the first and second quadrants (P≤0.01).There were no differences in percent of birds in the first quadrant onwk 1, but there were 3.3±1.07% greater LASER birds in this quadrant onwk 6, more than double the percent of control birds (P≤0.05). There were2.8±0.89% more control birds in the second quadrant on wk 1 (P≤0.05),but no differences in this quadrant on wk 6. There were no differencesdue to enrichment in quadrants 3 or 4 (Table E4).

TABLE E3 Human-approach paradigm (HAP) results; percent of Ross 308broilers Interacting vs Not Interacting and Not Interacting behaviorfurther classified using digital image evaluation. Values presented aswk × treatment LSMeans (pooled SEM) on wk 1 and 6. N = 80 observationsWeek 1 (%) Week 6 (%) P-value Behavior Control Laser Pooled SEM ControlLaser Pooled SEM Wk Wk * Trt Interacting  5.46  3.22 0.74  2.80  4.310.63  0.09 <0.01  Not interacting 94.00 96.33 2.18 96.93 95.09 2.19 0.70 0.35 Not interacting further classification Feeder  4.55  4.670.87  3.81  3.53 3.67  0.03 0.62 Drinker 10.62  6.94 1.03  3.35  5.130.59 <0.01 <0.01  Other 83.62 86.93 2.07 92.11 90.24 2.14 <0.01 0.22¹HAP was carried out on all pens once on wk 1 and once on wk 6. Anunfamiliar human entered the pen and after 15 s, a photograph was takento analyze the birds' response ²Data was collected in bird counts,converted to percent of birds in the pen exhibiting each behavior

TABLE E4 Human-approach paradigm (HAP) results; percent of Ross 308broilers present in each quadrant of the pen. Values presented as wk ×treatment LSMeans (pooled SEM) on wk 1 and 6. N = 80 observations Week 1(%) Week 6 (%) P-value Quadrant Control Laser Pooled SEM Control LaserPooled SEM Wk Wk * Trt 1  6.86  5.57 1.41  3.00  6.34 1.07 <0.01 <0.01 2 8.95  6.18 0.89 20.44 22.18 2.10 <0.01 <0.01 3 26.00 26.62 1.46 38.3836.07 1.86 <0.01  0.29 4 58.68 62.08 4.03 36.98 36.83 2.60 <0.01  0.36¹HAP was carried out on all pens once on wk l and once on wk 6. Anunfamiliar human entered the pen and after 15 s, a photograph was takento analyze the birds' response ²Data was collected in bird counts,converted to percent of birds in the pen exhibiting each behavior

4. DISCUSSION

Motivation is understood to be a process driven by bothexternal/environmental and internal/physiological factors resulting ingoal-oriented behavior or action (Toates, 1986). Motivation in broilerbirds, however, is not well understood. It has been shown that food andexploring novel objects motivates broilers (Newberry, 1999, Bokkers,2002; Bokkers, 2004). A combination of these motivations may have driventhe increase in active behavior seen every day in the first 9 d exceptd2 and 6 (FIG. 6A). Further, the performance of LASER birds was notcompromised but was improved, with an overall decrease of 0.07 FCRpoints and total increased weight gain of 0.24 kg/bird (Meyer, et al.,2019). Thus, the success of the novel laser device tested here inmotivating, not forcing an increase in active behavior and walkingdistance, is among the first to accomplish increased movement incombination with improved performance.

We hypothesize that this success may be due in part to the laser dotsstimulating pecking behavior, a documented response to small particlesin broilers (Hogan, 1973), or to visual-based foraging and predatorybehavior natural to the chicken's junglefowl ancestors(Fernandez-Juricic, 2004). Junglefowl continuously move while foraging(Arshad, 2000), a behavior that may have been replicated in broilerschoosing to follow lasers around the pen in this study. However, duringwk 6, there were no differences in proportion of active/inactivebehavior due to enrichment. This is likely a result of maximal bodyweight overriding motivation to move as birds neared the end of thegrow-out, rather than habituation to the lasers, as a similar pattern isobserved in declined use of perches after wk 5 in broilers (Bokkers,2003). Further, work in laying hens when exposed to environmentalenrichment in the form of strings for limited daily time periods (10min), rather than constant exposure, maintained interest in pecking atthe strings for 14 weeks (Jones, et al., 2000).

An interesting behavior pattern was detected in the weekly walkingdistance analysis where min 3 more closely followed min 1 than min 2 interms of increased distance walked, and LASER birds walked more than thecontrol wk 2-5 during this min (FIG. 10C). Hence, it appears thatrecording the distance walked during each min of the 4-min laser periodis necessary, as over time birds moved more in min 1 and 3 than 2 and 4.This likely contributed to the increased total distance walked duringlaser periods wk 2-5 by LASER focal birds (FIG. 10E), resulting in a215% increase in walking distance on wk 5, a notable outcome in birdsnearing-market weight.

As the device was entirely novel, a 4-min laser period was used with theintention to determine if this length of time was successful instimulating bird activity and walking distance. Our data indicate thatwithin the first 9 days, a 4-min period was effective in promotingwalking up to and including min 4. When viewing the entire 6-wkgrow-out, following wk 4 the increase in walking distance and activebehavior declined after min 3. Thus, it is possible that a 3-min laserperiod would suffice for broilers older than 4 wk, but for birds 4 wk oryounger, 4-min periods were effective. Although no difference inactivity was seen during wk 6 (d35-42), weight gain was increased by0.22 kg and FCR was decreased by 18 points in the critical finisherperiod (Meyer, et al. 2019). The increased weight gain of 0.24 kg/birdoverall could be translated to the range of $0.71-$1.39 more saleablebreast meat/bird, using current prices (USDA, 2019). Additionally, theinclusion of this device would not require altered management or humanlabor to increase bird activity and could be easily cleaned and re-usedover multiple flocks. Birds cannot physically interact with the device,hence no changes to biosecurity/cleaning are needed. This is practicalcompared to other forms of enrichment designed to stimulate activitythat must be cleaned or replaced within and between flocks, such asstraw bales (Kells, et al, 2001), pecking strings (Bailie and O'Connell,2015), or other novel objects (Altan, et al., 2013). Additionally, thelaser does not promote object-guarding behavior within the birdhierarchy.

The increased distance walked in proportion to the increase in activity(walking or running) makes it likely that LASER birds were moving at anincreased speed to account for this increased distance. Future studiesusing this device that incorporate a walking speed measure couldvalidate this hypothesis. In work by Dawkins and others (2009) anincreased walking speed, along with increased time spent walking,resulted in decreased lameness. However, in our research conditions, ascore of 2 was rare and no LASER birds received a 2, hence we did notdetect a difference due to laser enrichment. Taking into account theincreased weight gain and improved FCR in LASER birds (Meyer, et al.,2019), no detection of lameness is a positive outcome. These dataindicate that the paradigm postulated by Weeks et al. (2000) thatselection for improved FCR leads to less active animals, and thus morelameness, may have been counteracted by the increased exercisestimulated by the laser device.

The increase in feeder behavior seen in LASER birds on proportionallymore days/weeks is logical, as LASER birds had 0.02 kg greater feedintake in the starter period, 0.05 kg greater in the grower, and 0.14 kggreater in the finisher (Meyer, et al. 2019). Further, feeding latencyshowed that d0-8, approximately 71% of LASER focal birds were at thefeeder at least once either during or within 5 min following laserperiods. Over wk 1-6, 60.5% of LASER focal birds were at the feedereither during or shortly following laser periods. This is a positiveresult, along with the increased time spent at feeder in LASER birds,indicating that the device increased bird movement but may have alsoencouraged feeding, perhaps by stimulating natural foraging or predatorybehavior. In 3 4-min timepoints selected for behavior and walkingdistance analysis that were not during scheduled laser periods (06:30,18:30, and 22:30), LASER birds walked further than control birds on d1and wk 6, spent more time active on d1 and 3, and were at the feedermore on wk 4 and 5 (P<0.05, unpublished data). These data indicate amaintenance of activity and feeder behavior outside of the laserperiods.

The HAP was used here to measure fearfulness in the flock, a measurevalidated in swine by Weimer and others (2014), based on methods used inpigs and cattle by Hemsworth, et al. (1996). Results in these specieshave shown that animals with positive, regular interactions with humanswere quicker to approach, indicative of decreased fear. Environmentalenrichment has been shown to decrease fear responses in poultry, forexample reducing freezing, avoiding novel objects, and latency to enteran unfamiliar environment (Jones and Waddington, 1992). Classical music(a form of sensory enrichment) played to layer-type chicks decreasedtonic immobility duration and heterophil: lymphocyte ratio (Dávila, etal., 2011). However, in work by Bizeray, et al. (2002b) a barriertreatment increased tonic immobility (a measure of fearfulness inbirds). The “touch test” and “avoidance distance test” have beenvalidated in laying hens, where response to humans was positivelyinfluenced by more than minimal human contact (Graml, et al., 2008).Within this study, the overall proportion of control birds interactingwith the human decreased from wk 1 to 6, while the proportion of LASERbirds interacting increased.

A greater number of LASER birds were counted in quadrant 1, closest tothe unfamiliar human, during wk 6 than control birds. Importantly, therewas no evidence of piling, a negative behavior associated with fear inpoultry (Campbell, et al., 2016). However, this method requires furtherresearch in broilers and is likely to be more applicable in poultryspecies that naturally tend to approach people, such as commercialturkeys. Other stress markers, including measuring corticosteroneconcentrations from the serum or feathers, have been validated inbroilers and may be an alternative methodology for determining stress(Weimer, et al., 2018).

In summary, these data have provided strong evidence that this novelenvironmental enrichment device positively increased broiler birdphysical activity without impacting lameness. This unique tool motivatedbroilers to move of their own volition by stimulating them visually,encompassing physical, occupational, sensory, and nutritionalenrichment. The laser device is practical and applicable to commercialbarns without changing grow-out procedures or negatively impacting birdwelfare or performance.

REFERENCES REGARDING SECTION E

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F. Example 3—Data Regarding Use of Light Spots to Influence Conspecifics

With reference to FIGS. 11A and B, 12A and B, 13A and B, and 14A and B,further aspects according to the present invention are demonstrated.Experimental data indicates that application of methods and systemsaccording to earlier examples to a minority of poultry exposed to lightspots in the manner discussed herein, can influence similar responsesand/or benefits in conspecifics. As will be appreciated, the benefits tothe conspecifics can be at least substantially similar as to theminority and this can greatly benefit the entire population involvedeven though conspecifics do not visually obtain the spots in the way theminority does, or at all.

Experimental data sets showing subsets (conspecifics) of the totalpopulation, by age, exposed to the moving light spot or spots followingthe minority percentage of the total population are at FIGS. 11A-Bthrough 14A-B. A brief description of these Figures follows:

Laser Following Results

FIGS. 11A-B. Mean percent of birds in laser-enriched pens only activelyfollowing the laser¹ during 4-min laser-enrichment periods² over (A)d0-8 and (B) wk 1-6 ¹Laser following was defined as: A bird with headand body orientated towards laser dot(s) on the floor of pen with legsin forward motion at least one time during the minute being analyzed.Bird is moving in the direction of laser dot.²LSMeans presented areaveraged over min 1-4 of each laser-enrichment period.

FIGS. 12A-B. Mean percent of birds in laser-enriched pens only moving¹during 4-min laser-enrichment periods², excluding birds moving whileactively following the laser, over (A) d0-8 and (B) wk 1-6 ¹Bird movingwas defined as: Any bird with legs in forward motion; walking or runningat least once during minute being analyzed who is not directly followingor moving in the direction of the laser dots.²LSMeans presented areaveraged over min 1-4 of each laser-enrichment period.

FIGS. 13A-B. Mean percent of birds in laser-enriched pens only movingand/or following the laser¹ during 4-min laser-enrichment periods² over(A) d0-8 and (B) wk 1-6 ¹Birds moving were defined as: Any bird withlegs in forward motion; walking or running at least once during minutebeing analyzed, including birds directly following or moving in thedirection of the laser dots.²LSMeans presented are averaged over min 1-4of each laser-enrichment period.

FIGS. 14A-B. Mean duration of laser-following behavior¹ by individualfocal birds in laser-enriched pens only during 4-minute laser-enrichmentperiods² over (A) d0-8 and (b) wk 1-6 ¹ Laser-following was defined as:A bird with head and body orientated towards laser dot(s) on the floorof pen with legs in forward motion at least one time during the minutebeing analyzed. Bird is moving in the direction of laser dot.² LSMeanspresented are averaged over min 1-4 of each laser-enrichment period.

As can be seen by the foregoing, participation of a minority of poultryin visually acquiring and responding to one or more light spotsaccording to the present invention influences other poultry at or nearthat minority (conspecifics).

G. Additional Proof of Concept Data

The following is additional description regarding aspects of theinvention and its proof of concept, including experimental data.

1. Brief Data Summary of Laser Trial for Patent Consideration

a. Introduction: This study was designed to query a new enrichmentdevice (laser) for meat type poultry. A total of 1,200 broiler chickenswere raised through a traditional 6 week growth cycle, where half of thepens received the novel environmental enrichment (EE) device. Theproject was to determine if the EE device positively affected naturalbird behavior, but also their leg health and growth rate. The EE devicewas placed near the ceiling and emitted a concentrated red dot in aslow-moving, random pattern, designed to emulate natural predatorybehavior and stimulate active bird behavior. The laser itself is anon-dangerous, non-toxic method of stimulating movement and interest.Other current enrichment methods (straw bales, field tile, etc.) maypromote growth of unwanted pathogens on their surfaces and must bemoved, disinfected, or replaced with each flock. A subset of the birdswere labeled with food grade dye and videos captured laser and non-laserperiods to analyze movement and behavior. Throughout the 6-week trial,average performance (laser vs non-laser) was examined by calculatingFeed Conversion Ratio (FCR) and Average Daily Gain (ADG) based on penweights and measured feed intake. Behavior is being collected on focalbirds in each pen. Video was recorded daily for week one and then oneday a week for the following five weeks. Willingness to approach, footpad dermatitis, breast blisters, walking distance, walking lameness,bone mineral density, bone mineral content, and air and litter qualitywere measured throughout and/or upon trial completion.

b. Laser Specs & Images: Each laser unit emitted two laser dots thatrandomly moved within two replicate 1.2×2.4 m pens. The laser consistedof two separate red, 650 nm lasers that moved independently in a randompattern across both pens (a 2.4×2.4 m radius total). See FIGS. 1A-B, 2and 3. One side of the barn contained 20 laser pens, and the other sideof the barn contained 20 control pens.

c. Laser Schedule: The lasers turned on 4 times per day, 6 hours apart,for 4 minutes per “session” (Table G1). This schedule began on d0 of thetrial and remained constant for the entirety of the trial.

TABLE G1 Daily laser schedule Laser Session 1 5:30am-5:34am LaserSession 2 11:30am-11:34am Laser Session 3 5:30pm-5:34pm Laser Session 411:30pm-11:34pm

d. Performance: Outcomes: Pen weights were recorded biweekly on days 0,14, 28, and 42 of the trial, and feed disappearance was measuredthroughout the trial. Feed intake, weight gain, feed conversion ratio(FCR), and average daily gain (ADG) were calculated. 2-week performanceperiods were used; starter (d0-d14), grower (d14-d28), & finisher(d28-d42). On day 0, 30 chicks were placed in each pen and mortality wasrecorded throughout the trial.

e. Statistics: Data were analyzed using the Mixed procedure on SAS dueto normal distribution and are presented on a pen and averaged by birdbasis.

f. Results:

(1) Feed Intake: The effect of laser treatment was used to compare feedintake for each performance period of the trial (starter, grower,finisher) and overall feed intake for 42 days. Laser enrichment has asignificant effect on feed intake by pen during the starter period(d0-d14, P=0.0012) and pen intake during the finisher period (d28-42,P=0.0084), resulting in laser-treatment birds consuming more feed inboth cases, likely due to increased movement with laser enrichment instarter phase, and larger body size in the finisher phase (Table 2).Intake was averaged by bird number in the pen to provide an averageintake per bird. On a per bird basis, the laser treatment had asignificant effect on intake in every performance period and overall,with laser birds consuming more feed in all cases (4% more in starter;P<0.0001, 3.45% more in grower; P=0.0035, 3.66% more in finisher;P=0.0043, 3.82% more overall; P=0.0028). This increased intaketranslated to improved performance, with an 8.01% increase in ADG on aper bird basis (Table G3).

(2) Weight gain: Weight gain was compared between treatments on aper-pen basis, and laser-treated birds gained significantly more weightin the Grower period (P=0.0155), Finisher period (P<0.0001), and overall(P<0.0001). (Table G2). Weight gain was also averaged on a per birdbasis, in which the laser treatment had a significant effect on gain inevery period and overall, where each pen gained on average 8 kg more dueto laser enrichment (Starter; P=0.0427, Grower; P=0.0011, Finisher;P<0.0001, Overall; P<0.0001; Table 3). Improved feed intake and weightgain translates to increased flock productivity and significant incomefor a producer.

(3) FCR: FCR was calculated for each performance period and overall bypen, the laser-treatment pens had significantly better FCRs in thegrower period (P=0.0313), finisher period (P<0.0001), and overall(P<0.0001). (Table 2). This translates to increased profits for theproducer and contracted company. An improvement of 7 points of FCR dueto the laser enrichment treatment is hugely significant in the poultryindustry because of the multiplier effect of billions of birds producedeach year. Feed represents 80% of the cost of production to the company;hence, even 1 point of improvement in FCR is significant. On a penbasis, overall production cycle FCR was improved by 4.59% (7 FCR points)in birds enriched with laser enrichment. In the grower and finisherperiods, respectively, FCR was significantly improved by 2% (3 FCRpoints) and 10% (19 FCR points) due to laser enrichment (P<0.0001).

(4) ADG: Average daily gain (ADG) was calculated on a per pen andaveraged per bird basis; pens in the control category had significantlylower ADGs in the finisher period (P<0.0001) and overall (P<0.0001).(Tables G2 and G3). Laser enrichment lead to an 8.02% improvement in ADGfor the overall period, with a significant 14% improvement in AGD in thefinisher period due to enrichment. Birds in the control (non-laser)category had lower daily gains in the starter period (P=0.0475),finisher period (P<0.0001), and overall throughout the trial (P<0.0001).Average daily gain (kg/pen) was 2.8848 (control) vs 3.3545 (enrichment),with an overall ADG of 1.9634 vs. 2.1345 in enriched birds (P<0.0001).

Performance: Table G2. Average intake, gains, FCR, & ADG by pen (kg)Performance measure Control SEM Laser SEM P-value Starter Intake 14.34130.1134 14.8305 0.0817  0.0012* Grower Intake 46.5895 0.3793 47.79560.5599  0.0762  Finisher Intake 77.4193 1.0104 81.2898 0.9574  0.0084*Overall Intake 138.32 1.3363 143.84 1.3340  0.0058  Starter Gain 11.10000.1307 11.3033 0.1142  0.2489  Grower Gain 31.3200 0.3029 32.64720.4384  0.0155* Finisher Gain 40.3872 0.6317 46.9635 0.6265  <.0001*Overall Gain 82.4635 0.9564 89.6492 0.8291  <.0001* Starter FCR 1.29360.0088 1.3135 0.0087  0.1187  Grower FCR 1.4882 0.0069 1.4648 0.0078 0.0313* Finisher FCR 1.9209 0.0227 1.7351 0.0255  <.0001* Overall FCR1.6787 0.0111 1.6050 0.0098  <.0001* Starter ADG 0.7929 0.0093 0.80740.00816 0.2489  Grower ADG 2.2126 0.0320 2.2416 0.04861 0.6209  FinisherADG 2.8848 0.0451 3.3545 0.04475 <.0001* Overall ADG 1.9634 0.02282.1345 0.0197  <.0001* *P < 0.05 denotes significance

TABLE G3 Average intake, gains, & ADG per bird (kg) Performance measureControl SEM Laser SEM P-value Starter Intake 0.4797  0.0037 0.5010 0.0018 <.0001* Grower Intake 1.5572  0.0117 1.6128  0.0133 0.0035*Finisher Intake 2.6245  0.0317 2.7554  0.0291 0.0043* Overall Intake4.6897  0.0428 4.8760  0.0394 0.0028* Starter Gain 0.3712  0.00420.3818  0.0027 0.0427* Grower Gain 1.0357  0.0140 1.1015  0.0108 0.0011*Finisher Gain 1.3688  0.0194 1.5915  0.0175 <.0001* Overall Gain 2.7951 0.0275 3.0388  0.0235 <.0001* Starter ADG 0.02653 0.0003 0.02726 0.00020.0475* Grower ADG 0.07398 0.0010 0.07559 0.0016 0.3899  Finisher ADG0.09920 0.0014 0.1143  0.0012 <.0001* Overall ADG 0.06657 0.0007 0.072370.0006 <.0001* *P < 0.05 denotes significance

(5) Summary: The presence of laser activity environmental enrichment inthe broiler pens 4 times a day led to significantly higher feed intakein the starter and finisher period (by pen), but significantly greatergains in the grower and finisher period that made laser-treated birdsheavier overall with improved FCR and improved ADG. The feed conversionwas more efficient in the grower and finisher periods and overall forthe birds exposed to laser enrichment, and average daily gain wasincreased in the finisher period (and overall). See also FIGS. 15-17.

3. Behavior Outcomes:

a. Willingness to approach (WTA): Outcomes: On Weeks 1 and 6 of thetrial, a Willingness to Approach test was conducted in all 40 pens (20laser pens, 20 control pens, n=80 total observations). In this test, thesame researcher entered each pen quietly and crouched facing the birdsfor 15 seconds. At the end of 15 seconds, the researcher looked uptowards the birds, and a separate individual (outside of the pen) took aphotographic image at the exact moment the researcher looked up. Theseimages were later analyzed based on the birds' behaviors and whether ornot they were interacting with the researcher (facing towards orphysically touching), or not interacting (facing away). Birds notinteracting were further classified into at the feeder, at the drinker,or “other” behaviors. Finally, then pen was broken down into four0.6×1.2 m quadrants and the number (%) of birds was calculated. Thequadrant nearest to the researcher was the first quadrant and thequadrant furthest from the researcher was the fourth quadrant.

b. Statistics: WTA data were analyzed by week, treatment, andinteraction of week by treatment using the Glimmix Procedure on SASbecause the data were not normally distributed (Poisson's distribution).

c. Results: Interacting versus not interacting: Birds interacting withthe human was significantly affected by the interaction of week bytreatment (P≤0.0214). Interacting birds decreased from weeks 1 to 6 inthe control group but increased between weeks 1 to 6 in the laser group(Table G4, FIGS. 18A and 18B, 19A and 19B, and 20). Data were alsoanalyzed as percentages of birds interacting vs. not interacting, and asignificant effect of week by treatment was seen again in theinteracting category (P<0.0001). See Table G7.

d. Not interacting bird activity: The number of birds at the feeder wasnot affected by week, treatment, or week by treatment, but birds at thedrinkers was significantly affected by week (p=0.0002) and week bytreatment (0.0284). Birds at the drinker decreased in both laser andcontrol pens from weeks 1 to 6 but decreased more drastically in thecontrol group. (Table G5).

The percentage of birds at the feeder, was affected by week (P=0.0301).The percentage of birds at the drinker was affected by week (P<0.0001)and week by treatment (P<0.0001), with birds at the drinker decreasingmore drastically in the control—than in the laser group. Birds in theother category was significantly affected by week (P=0.0077), with agreater percentage present in this category for both treatment groups.(Table E6).

e. Quadrants of the pen: Bird count in the first quarter was affected bythe week by treatment interaction (P=0.0092), with the number of birdsin first quadrant decreasing between weeks 1 & 6 in the control groupand increasing in the laser group. However, only week had an effect onbird number in the second (P<0.001), third (P<0.0001), and fourth(P<0.0001) quadrants (Table G6). On a percentage basis, week had asignificant effect on all quadrants (first; P=0.0002, second; P=<0.0001,third; P<0.0001, fourth; P<0.001), and the effect of week by treatmentwas also significant on the percent of birds present in the first(P=<0.0001) and second (P=0.0015) quadrants (Table G6). Some of theeffect due to week can be attributed to increased body size in thebroilers and less space for them to move in the pen.

TABLE G4 Willingness to approach; number of birds interacting vs notinteracting means and percentages, n = 80 observations Control Laser Pvalue Behavior Week 1 Week 6 Week 1 Week 6 Week Treatment Week *Treatment Interacting, number  1.80  0.90  1.10 1.45 0.31 0.97  0.0214*Not interacting, number 28.20 28.65 28.90 28.15 0.90 0.93 0.6181Interacting %  5.46%  2.80  3.22  4.31 0.09 0.83 <0.0001* Notinteracting % 94.00% 96.93 96.333 95.10 0.71 0.91 0.3453 *P < 0.05Behavior data are presented as means (average number of birds) and aspercentage of birds in the pen. Note: Birds not visible were combinedinto not interacting category (Means of “not visible” birds by treatmentand week: Control Week 1; 0.55, Control Week 6; 0.15, Laser Week 1; 0.9,Laser Week 6; 0.05).

TABLE G5 Willingness to approach; not interacting behavior in birdcounts (#) & percentages Control Laser P value Behavior Week 1 Week 6Week 1 Week 6 Week Tx Week * Tx Feeder # 1.43 1.23 1.57 1.18 0.26310.9152 0.7188 Drinker # 3.05 1.00 2.05 1.50  0.0002* 0.9816  0.0284*Other # 23.15  26.25  24.35  25.40  0.0696 0.8457 0.3592 Feeder % 4.553.81 4.6702% 3.53  0.0301* 0.9205 0.6242 Drinker % 10.62  3.35 6.94 5.13<0.0001* 0.9992 <0.0001* Other % 83.62  92.11  86.93  90.24   0.0077*0.702  0.2207 *P < 0.05Abbreviations: Tx=treatment. Behavior data are presented as means(average member of birds) and as percentage of birds in the pen. Thenumber of birds categorized as “piling” was combined into “Other”behavior (Means of birds “piling” by treatment and week: Control Week 1;4, Control Week 6; 0, Laser Week 1; 4, Laser Week 6; 4). Note that theseeach occurred in one pen, and no more than 4 birds were ever observedpiling.

TABLE G6 Willingness to approach; number and percentage of birds presentin each quadrant of the pen Control Laser P value Behavior Week 1 Week 6Week 1 Week 6 Week Tx Week * Tx First, number 2.23 1.0524 1.78  2.040.0648 0.4408  0.0092* First % 6.86 2.99 5.57  6.34  0.0002* 0.3944<0.0001* Second, number 2.52 6.1883 1.79  6.42 <0.0001* 0.2951 0.1389Second % 8.95 20.44 6.18 22.18 <0.0001* 0.3066  0.0015* Third, number7.20 11.00 7.55 10.20 <0.0001* 0.8543 0.4226 Third % 25.99  38.38 26.62136.07 <0.0001* 0.7646 0.2918 Fourth, number 16.84  10.76 17.56  10.47<0.0001* 0.9376 0.5718 Fourth % 58.68  36.98 62.08  36.83 <0.0001*0.7765 0.361  *P < 0.05Abbreviations: Tx=treatment. Behavior data are presented as means(average number of birds) and as percentage of birds in the pen. Note:The pen was broken down into 0.6 by 1.2 m quarters with the firstquarter being the section of the pen the human was in and the fourthbeing the opposite end (most distant from the human).

Further data is shown in Table G7 below:

TABLE G7 Human approach paradigm: LSMeans (SEM) and percentage ofbroilers interacting vs. not interacting and not interacting furtherclassification. Control Laser P values Behavior¹ Week 1 SEM Week 6 SEMWeek 1 SEM Week 6 SEM Week Treatment Week * Treatment Interacting Number 1.80 0.30  0.90 0.21  1.10 0.24  1.45 0.27 0.31 0.97  0.02* Percent 5.46 0.89  2.80 0.52  3.22 0.58  4.31 0.73 0.09 0.83 <0.01* Notinteracting² Number 28.20 1.19 28.65 1.20  28.9 1.20 28.15 1.19 0.900.93 0.62 Percent 94.00 2.17 96.93 2.20 96.33 2.19 95.09 2.18 0.70 0.910.35 Not-interacting further classification Feeder Number  1.43 0.29 1.23 0.27  1.57 0.31  1.18 0.26 0.26 0.92 0.72 Percent  4.55 0.86  3.810.73  4.67 0.87  3.53 0.69  0.03* 0.92 0.62 Drinker Number  3.05 0.39 1.00 0.22  2.05 0.32  1.50 0.27  0.01* 0.98  0.03* Percent 10.62 1.20 3.35 0.50  6.94 0.86  5.13 0.68 <0.01* 0.10 <0.01* Other³ Number 23.151.08 26.25 1.15 24.35 1.10 25.40 1.13 0.07 0.85 0.36 Percent 83.62 2.0492.11 2.15 86.93 2.08 90.24 2.12  0.01* 0.70 0.22 *P < 0.05 ¹Behaviordata are presented as means (average number of birds) and as percentageof birds in the pen. ²Birds not visible were combined into notinteracting category (Means of “not visible” birds by treatment andweek: Control Week 1; 0.55, Control Week 6; 0.15, Laser Week 1; 0.9,Laser Week 6; 0.05). ³The number of birds categorized as “piling” wascombined into “Other” behavior (Means of birds “piling” by treatment andweek: Control Week 1; 4, Control Week 6; 0, Laser Week 1; 4, Laser Week6; 4). Note that these each occurred in one pen, and no more than 4birds were ever observed piling.

f. Summary: Our willingness to approach data imply that the lasertreatment may have made birds become more willing to “interact” with thehuman in their pen from the first week to the last week of the trial,whereas the non-laser (control) birds became less inclined to interact.The interaction of week and laser treatment also affected the number ofbirds present at the waterer, with more control birds at the drinker inweek 1 and more laser birds at the drinker in week 6. The data regardingbirds present in each quadrant of the pen likely represent a drasticincrease in bird size from the start to the end of the trial, meaningthat the larger the birds grew, the more space in the pen they filledwhether they were truly more inclined to be closer to the researcher ornot.

4. Breast Blister & Footpad Dermatitis:

a. Outcomes: Five focal birds per pen (randomly assigned at the start ofthe trial) were examined weekly, and all birds at the conclusion of thetrial, for the presence of breast blisters and the occurrence of footpaddermatitis. Both examinations took place on the same focal birds at thesame time each week. Footpad dermatitis was scored using the AmericanAssociation of Avian Pathologists Paw Scoring described in Table D8, andbreast blisters were scored according to guidelines listed below.

TABLE G8 Footpad dermatitis scoring system Pass Fail Normal colorErosions, ulcerations, scabs Slight discoloration HemorrhagesThickening/hyperkeratosis Swelling of footpad Area <½ footpad Area >½footpad

Breast blisters were considered present when:

Equal to or larger than 0.5 cm²

One or more breast burns

Scabs on breast skin

-   -   Mild: brownish-colored scab    -   Severe: ulcer with black exudates

b. Results: Neither footpad dermatitis nor breast blisters were observedfor either treatment group in weeks 1 through 6. Randomly selected focalbirds as their breast and feet conditions were examined (Note: breastand feet image for each week do not always display the same bird andrepresent both treatment groups, birds were chosen for images randomly).

c. Summary: The laser treatment had no effects (positive or negative) onbreast and foot condition in our study, as no birds for the entirety ofthe trial were observed to have blisters or dermatitis. While ourresearch facility used clean litter for this study, and this cancontribute to the lack of blisters and dermatitis, a positive outcome ofthis work is that increased movement in laser enrichment did notnegatively affect breast blisters or foot condition. Chicken feet (paws)comprise a significant portion of the exports to overseas markets.

It is to be understood that the experimental data here was obtainedusing relatively clean litter in the pens. It is more typical industrypractice to have used litter. These results may not have seensignificant breast blister/footpad issues due to this relatively cleanlitter and very clean research settings.

5. Walking Lameness:

a. Outcomes: The 5 focal birds per pen were examined for lameness weeklyusing the National Chicken Council Audit Guidelines adapted to Table G9.Birds were removed from their home pens and placed into a unique,custom-built walkway designed for minimal distractions and ease ofassessment. This structure was 1.8 m long with 0.46 m walls that allowedfor 15.24 cm each of “start” and “finish” space for broilers, and ˜1.524m measurements drawn on the floor to measure exactly where lame birdsstopped walking.

On Week 1, all 5 birds were put on the walkway and examined for lamenessat the same time, but for weeks 2-6 birds were assessed in groups of 2or 3 for increased efficiency as the birds grew and became morereluctant to walk.

TABLE G9 Walking Lameness Scoring System Score Defined 0 Bird walks1.524 meters with no visible signs of lameness 1 Bird walks 1.524meters, but appears uneven in steps or sits down to rest 2 Bird will notor cannot walk 1.524 meters, obvious lameness. Distance recorded.

b. Statistics: Data were compiled and analyzed using the frequency andchi square procedures of SAS because the data were so abnormallydistributed, they could not be analyzed otherwise (so few birds with ascore or 1 or 2).

c. Results: The majority of birds were scored a 0 regardless oftreatment, although there were a slightly higher number of birds in thecontrol category given this rating overall. Birds in the laser treatmenthad a greater occurrence of a score of 1 but had no occurrence of birdsscored 2. Two control birds received a score of 2 (Table G10).

TABLE G10 Number of birds in each lameness category over 6 weeks ScoreControl Laser Total 0 202 198 400 1 6 12 18 2 2 0 2

d. Chi square test of independence: There was no effect of treatment onwalking lameness score (P=0.1372).

e. Summary: Our data indicate that the laser treatment did not have ameasurable lameness effect in our flock. In this study there are so fewlameness cases that these results may not be representative of a largercommercial flock with a greater lameness prevalence. We did see a highernumber of score 1 birds in the laser group (2 in total), but no laserenriched birds scored a 2. See FIG. 21.

7. Bone density and bone mineral content of tibia:

a. Outcomes: Upon conclusion of the trial (d 42) the right tibia wascollected from all focal birds (70) and underwent a DXA scan todetermine bone mineral density and bone mineral content. Bone mineraldensity is a measure of quality of the bone present, and bone mineralcontent is reflective of size of the bone and thus related tosize/weight of the bird. Ideally, birds in the laser treatment groupwould see increased bone mineral density due to increased activity.

b. Statistics: Bone mineral density and bone mineral content values wereanalyzed using the Mixed procedure of SAS due to normal distribution.

c. Results: There were no observed differences in the average bonemineral density or bone mineral content values based on control or lasertreatment. Numerically, the laser group had a higher density and contenton average (Table G11).

TABLE G11 Bone mineral density (BMD) and bone mineral content (BMC) oftibia means analyzed by treatment Performance measure Control LaserP-value BMD (g/cm²) 0.1291 0.1376 0.2034 BMC (g) 0.9746 1.1070 0.2365

d. Summary: In our study, enclosure arrangement, and stocking density,the laser enrichment device did not significantly increase the bonedensity of the tibia nor the bone mineral content. See FIGS. 22 and 23.

8. Air & Litter Quality Measurements:

a. Outcomes: The amount of ammonia in the air on each side of the barnwas measured weekly in the front, middle, and back of each side with ahand-held ammonia reader and additionally, ammonia test strips. Litterquality was analyzed weekly (different pens than those used for ammoniatests) according to the National Chicken Council Audit Guidelines:

-   -   Litter moisture evaluated in different pens on each side of the        barn, not around or directly under the water line.    -   Litter was gathered from several different sections of the pens        analyzed.    -   Litter should be “loosely compacted when squeezed in the hand.        If the litter remains in a clump when it is squeezed in the        hand, it is too wet” (NCC).

b. Statistics: Data was compiled using the frequency and chi squareprocedures of SAS because of the small number of data points and natureof the comparison.

c. Results: Ammonia reader: There were no significant differences (chisquare) in the ammonia readings from the laser and control sides of thebarn (Table G12). Ammonia levels in commercial barns are typicallyhigher than seen here due to reused litter and changes in ventilationduring the grow-out cycle. They also depend on seasonal changes inrequired ventilation based on the geographic location of the barn(changes in ability to ventilate during the winter in the Midwest, forexample). The maximum allowed in barns is set at 25 ppm, while chickenscan be negatively influenced at long-term exposure of 20 ppm.

d. Ammonia test strips: There were no significant differences (chisquare) in the test strip readings from the laser and control sides ofthe barn. Descriptive data in Table G12.

e. Litter moisture: There were no differences in the litter evaluationsfrom the laser and control sides of the barn; both sides passed thelitter quality guidelines every week and conditions were no different.

TABLE G12 Average air ammonia results measured at bird height using twomethods: a handheld ammonia reader and ammonia test strips listed byweek (ppm) Control Laser Week Reader Test Strips Reader Test Strips Week2 0 5 0 5 Week 3 0 5 0 5 Week 4 0 5 0 5 Week 5 3 10 3 10 Week 6 8 17 417

f. Summary: The laser treatment had no effect on the amount of ammoniapresent in the air at bird height (measured with 2 methods) nor thequality of the litter. Importantly, implementation of this enrichmentdevice did not, in our conditions, cause an increase in ammonia due topossible increased activity of birds, which is an important welfareconcern for producers.

g. Home Pen Behavior: Outcomes: One focal bird per recorded pen (7 laserpens, 7 control pens, 14 birds total) was observed for four laserperiods (4 minutes each) daily for week 1 and one day a week for weeks2-6 using a predetermined behavior ethogram (Table G13). Each behaviorperformed was recorded in the units of frequency (number of times thebird performed a certain activity) and duration (length of time spent oneach activity, in seconds). The duration of each behavior was thenconverted to percentage of the bird's time spent out of the 4 minutes.

h. Statistics: Focal bird behavior was analyzed using the Glimmixprocedure of SAS (9.4) due to lack of normal distribution of data.Certain behavioral measures (identified in Tables G13-15) were analyzedusing relaxed convergence criteria as labeled due to few occurrences ofsaid behaviors or were so rare that data could not be analyzed and ispresented descriptively. See also FIGS. 24-28.

TABLE G13 Ethogram for broiler bird behavior Measure, % & SecondsDefined Unit Active Legs are in forward motion (walking or Frequency,running) duration* Inactive Bird standing in one place or resting theFrequency, Social abdomen on the litter, head rested or raised¹ durationwhile any part of its body is in contact with another bird Inactive Birdstanding in one place or resting the Frequency, Isolated abdomen on thelitter, head rested (against duration chest or litter) or raised withoutany part of its body contacting another bird At Feeder Bird head overthe feeder circle, bird in Frequency, feeder or standing on feeder trayduration At Drinker Bird is standing beneath drinker line Frequency,duration Preening Dust bathing or head/beak twisted around in Frequency,contact with feathers duration Other Any behavior not otherwiseidentified Frequency, duration Out of View Focal bird was obstructed ornot observed Frequency, due to being under the heat lamp or insideduration the feeder on the left side that could not be seen from thecamera ¹H. H. Kristensen et al./Applied Animal Behaviour Science 103(2007) 75-89 *Activity will be further quantified by counting the numberof 0.6 by 0.6 meter gridlines crossed by the focal bird during the4-minute clip.

TABLE G14 Home pen behavior of focal bird during enrichment periods byweek: LSMeans (SEM) of frequency, duration (s), and % of time BehaviorControl Laser P values Week (across) 1 2 3 4 5 6 1 2 3 4 5 6 Week TrtWk * Trt Gridlines 3.01 2.75 2.29 1.62 1.73 1.51 4.36 5.15 3.92 2.312.21 1.40 <.01* 0.04* 0.14 SEM 0.46 0.39 0.35 0.28 0.29 0.27 0.60 0.730.51 0.35 0.34 0.25 Inactive social Frequency 1.14 0.32 0.43 0.57 0.430.50 1.51 0.76 0.82 0.78 0.78 0.35 <.01* 0.04* 0.37 SEM 0.24 0.11 0.130.15 0.13 0.14 0.29 0.22 0.18 0.17 0.17 0.11 Duration 32.64 26.18 25.6779.28 36.92 67.45 23.63 33.60 55.32 81.140 59.0 64.65 <.01* 0.33 <.01*SEM 4.51 3.60 3.54 10.66 5.03 9.09 3.32 4.69 7.48 10.91 7.97 8.72Percent 13.62 10.92 10.71 33.08 15.41 28.15 9.85 14.02 23.08 33.85 24.6126.97 <.01* 0.33 <.01* SEM 1.96 1.56 1.53 4.49 2.15 3.83 1.47 2.07 3.174.59 3.37 3.68 Inactive isolated Frequency 3.21 1.52 1.10 0.78 0.92 0.673.10 2.35 1.72 0.88 1.09 0.84 <.01* 0.17 0.53 SEM 0.47 0.26 0.22 0.180.20 0.19 0.47 0.43 0.29 0.19 0.22 0.19 Duration¹ 119.31 95.81 107.476.06 122.8 102.4 58.78 84.8 93.91 85.74 49.07 89.55 <.01* 0.06 <.01*SEM 13.15 10.55 11.81 8.41 13.48 11.27 6.59 9.56 10.34 9.46 5.48 9.87Percent¹ 49.73 39.93 44.77 31.7 51.18 42.69 24.52 35.27 39.17 35.7620.47 37.36 <.01* .06 <.01* SEM 5.57 4.46 4.99 3.58 5.68 4.76 2.86 4.164.38 4.01 2.36 4.18 Active Frequency 4.06 1.66 1.38 0.71 0.92 0.39 5.762.96 2.63 1.28 1.84 0.55 <.01* .01* 0.75 SEM 0.59 0.29 0.26 0.17 0.200.12 0.77 0.50 0.40 0.24 0.31 0.15 Duration 25.95 25.58 12.59 6.81 8.383.49 28.04 54.42 32.25 12.88 15.24 3.39 <.01* 0.05* <0.01* SEM 4.27 4.182.11 1.19 1.44 0.65 4.61 8.85 5.23 2.15 2.52 0.63 Percent 10.84 10.695.26 2.84 3.50 1.46 11.73 22.9 13.5 5.39 6.38 1.42 <.01* 0.05 <.01* SEM1.83 1.78 0.92 0.54 0.65 0.32 1.98 3.78 2.21 0.94 1.1 0.31 PreeningFrequency 0.97 0.20 0.15 0.03 0.06 0.17 0.51 0.14 0.10 0.06 0.10 0.13<.01* 0.89 0.80 SEM 0.35 0.10 0.08 0.03 0.04 0.09 0.22 0.09 0.06 0.050.06 0.07 Duration 3.13 2.92 0.84 0.53 0.96 1.94 1.71 0.78 1.98 0.470.78 2.51 <.01* 0.87 <.01* SEM 2.48 2.31 0.67 0.43 0.76 1.53 1.36 0.631.57 0.38 0.63 1.98 Percent 1.59 1.48 0.43 0.27 0.49 0.98 0.82 0.37 0.940.22 0.37 1.20 <.01* 0.80 <.01* SEM 1.08 1.0 0.30 0.19 0.34 0.67 0.560.27 0.64 0.16 0.26 0.81 At feeder Frequency 0.42 0.39 0.42 0.53 0.390.28 0.94 0.60 0.63 0.49 0.74 0.35 0.38 0.10 0.67 SEM 0.15 0.12 0.130.15 0.12 0.10 0.24 0.20 0.16 0.14 0.18 0.12 Duration² 24.47 44.83 49.5444.93 16.91 38.07 27.41 35.71 31.26 36.67 58.64 37.17 <.01* 0.80 <.01*SEM 5.08 9.21 10.17 9.23 3.52 7.83 5.69 7.40 6.45 7.55 12.02 7.65Percent 10.22 18.73 20.07 18.77 7.07 15.91 11.43 14.91 13.03 15.29 24.4515.5 <.01* 0.81 <.01* SEM 2.17 3.87 4.27 3.88 1.51 3.3 2.43 3.15 2.723.18 5.03 3.22 At drinker Frequency 0.75 0.39 0.53 0.18 0.53 0.18 1.240.31 0.39 0.32 0.53 0.25 <.01* 0.51 0.57 SEM 0.2 0.12 0.14 0.08 0.140.08 0.27 0.14 0.12 0.11 0.14 0.10 Duration 13.72 14.88 27.07 8.40 40.399.48 29.18 8.40 8.21 8.21 31.88 26.6 <.01* 0.88 <.01* SEM 2.58 2.76 4.951.6 7.34 1.79 5.36 1.67 1.56 1.56 5.814 4.87 Percent 5.73 6.22 11.313.51 16.87 3.96 12.21 3.51 3.43 3.43 13.33 11.12 <.01* 0.88 <.01* SEM1.14 1.19 2.10 0.71 3.09 0.79 2.3 0.78 0.70 0.70 2.46 2.07 *P ≤ 0.05¹Convergence criteria relaxed to 10⁻⁷ ²Convergence criteria relaxed to10⁻⁶ **Behaviors categorized as “Other” or “Out of view” were soinfrequent that the data could not be analyzed, relaxed convergencecriteria was attempted to 10⁻⁴. The mean for frequency of “Other”behavior for week 1 was 0.27 (±0.59), and the means were 0 (±0) forweeks 2-6 (behavior did not occur). The means for frequency of “Out ofview” for weeks 1 through 6 respectively were 0.27(±0.55), 0.05(±0.21),0(±0), 0.04(±0.19), 0.05(±0.23), and 0.02(±0.13).

TABLE G15 Focal bird home pen behavior during enrichment periods by day:LSMeans (SEM) of frequency, duration (s), and % of time days 0-8 ControlLaser P-values Behavior 0 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 8 Day TrtDay * Trt Gridlines 0.7 0.97 2.97 1.81 1.42 2.47 2.08 2.71 3.21 3.717.69 4.25 4.15 5.7 3.21 2.47 3.77 4.54 <.01* <.01* <.01* SEM 0.23 0.380.5 0.32 0.28 0.41 0.38 0.44 0.5 0.66 1.35 0.66 0.6 0.79 0.5 0.4 0.560.72 Inactive social Frequency 1.41 1.69 1.13 1.2 0.77 1.37 1.33 0.560.73 1.65 3.71 1.48 1.89 1.83 1.75 2.09 0.94 0.8 <.01* 0.04* 0.56 SEM0.35 0.52 0.26 0.24 0.19 0.27 0.28 0.15 0.18 0.38 0.82 0.31 0.33 0.330.32 0.35 0.22 0.23 Duration¹ 97.59 49.42 33.13 63.18 45.17 55.18 41.0215.63 40.53 113.1 67.22 23.77 38.71 32.7 65.08 56.6 21.18 50.58 <.01*0.81 <.01* SEM 10.49 5.77 3.66 6.74 4.87 5.9 4.46 1.79 4.39 12.11 7.642.7 4.19 3.58 6.95 6.06 2.41 5.59 Percent 40.7 20.61 13.82 26.35 18.8523.02 17.13 6.52 16.9 47.18 28.03 9.91 16.15 13.64 27.15 23.6 8.83 21.08<.01* 0.81 <.01* SEM 4.52 2.72 1.63 2.88 2.11 2.54 1.95 0.82 1.91 5.23.5 1.24 1.83 1.58 2.98 2.6 1.11 2.49 Inactive isolated Frequency 1.270.7 3.2 1.8 1.68 2.04 3.05 2.08 1.31 1.77 2.68 3.09 3.6 4.16 2.71 2.332.32 1.4 <.01* 0.02* <.01* SEM 0.31 0.32 0.46 029 0.28 0.31 0.43 0.310.24 0.38 0.65 0.46 0.45 0.51 0.38 0.34 0.37 0.3 Duration¹ 93.19 72.33120.3 93.79 102.9 74.12 106.8 78.46 111.3 71.07 43.33 59.74 82.49 65.838.26 52.14 78.32 65.1 <.01* <.01* <.01* SEM 8.56 7.1 10.81 8.42 9.236.7 9.6 7.08 9.96 6.61 4.52 5.5 7.43 6 3.56 4.77 7.12 6.12 Percent 38.8430.14 50.14 39.09 42.89 30.89 44.5 32.7 27.08 29.64 18.07 24.92 34.4127.45 15.96 21.75 32.66 27.08 <.01* <.01* <.01* SEM 3.76 3.33 4.62 3.593.93 2.88 4.1 3.04 4.23 2.95 2.23 2.43 3.19 2.59 1.59 2.08 3.09 2.75Active Frequency 1.95 1.81 3.99 2.61 2.32 3.66 4.5 2.19 1.86 3.44 6.895.77 5.87 7.47 5.51 4.46 3.63 2.17 <.01* <.01* <.01* SEM 0.41 0.53 0.560.38 0.36 0.49 0.6 0.34 0.31 0.58 1.16 0.75 0.7 0.85 0.67 0.56 0.52 0.4Duration 11.53 11.19 26.2 12.26 11.58 13.26 18.87 16.44 21.41 34.9843.64 29.13 30.2 36.23 19.66 17.03 58.25 60.89 <.01* <.01* <.01* SEM1.38 1.61 2.63 1.29 1.24 1.38 1.95 1.68 2.14 3.55 4.68 2.91 2.94 3.51.99 1.73 5.54 5.89 Percent 4.82 4.68 10.95 5.12 4.84 5.54 7.86 6.878.96 14.59 18.2 12.15 12.6 15.11 8.2 7.1 24.29 25.45 <.01* <.01* <.01*SEM 0.72 0.91 1.21 0.62 0.6 0.66 0.91 0.78 0.98 1.64 2.27 1.33 1.3 1.540.92 0.8 2.4 2.6 Preening Frequency 0.21 0.56 1.18 0.67 0.58 0.81 0.790.21 0.4 0.35 0.71 0.55 1.2 1.22 0.61 0.81 0.18 0.06 <.01* 0.63 0.02*SEM 0.12 0.29 0.26 0.16 0.15 0.18 0.2 0.09 0.13 0.16 0.32 0.17 0.23 0.240.16 0.18 0.09 0.06 Duration 0.62 4.8 9.33 5.32 2.01 6.72 4.72 1.17 71.43 1.77 2.95 6.72 4.86 3.02 4.16 1.37 1.75 <.01* 0.2 <.01* SEM 0.22 11.32 0.78 0.36 0.96 0.74 0.25 1 0.36 0.54 0.52 0.96 0.73 0.5 0.64 0.30.39 Percent 0.26 2.02 3.91 2.23 0.84 2.82 1.96 0.49 2.94 0.6 0.75 1.242.83 2.05 1.27 1.75 0.6 0.74 <.01* 0.23 <.01* SEM 0.14 0.58 0.62 0.380.2 0.45 0.37 0.14 0.47 0.22 0.33 0.29 0.45 0.37 0.27 0.32 0.17 0.23 Atdrinker Frequency 0.48 0.95 0.73 0.65 0.91 1.16 0.65 0.58 0.77 0.21 0.691.2 1 1.64 1.19 1.1 0.57 0.38 <.01* 0.94 0.11 SEM 0.19 0.38 0.21 0.170.22 0.26 0.19 0.16 0.2 0.12 0.32 0.29 0.23 0.34 0.27 0.25 0.18 0.15Duration 6.45 78.15 13.72 16.25 44.04 39.21 16.45 46.4 20.53 1.13 16.7929.96 25.49 38.74 23.79 45.08 9.61 10.91 <.01* 0.09 <.01* SEM 1.24 13.252.39 2.77 7.35 6.55 2.82 7.73 3.48 0.33 3.14 5.07 4.29 6.48 4.02 7.521.71 1.96 Percent 2.69 32.61 5.72 6.78 18.38 16.36 6.86 19.36 8.57 0.477.01 12.51 10.64 16.17 9.93 18.82 4.01 4.55 <.01* 0.1 <.01* SEM 0.615.72 1.06 1.21 3.11 2.78 1.23 3.27 1.5 0.19 1.5 2.18 1.84 2.76 1.73 3.180.78 0.9 *P ≤ 0.05 ¹Convergence criteria relaxed to 10⁻⁵ **Behaviorscategorized as “At the feeder”; both “Feeder 1” (traditional roundfeeders) and “Feeder 2” (feeder tray for chicks) behaviors were soinfrequent in days 0-8 that data could not be analyzed; convergencecriteria was attempted 10⁻⁴. The means for frequency of “Feeder 1” ondays 0-8, respectivley are 0.11(±0.42), 0.57(±1.09), 0.68(±0.91),0.46(±0.76), 0.52(±0.8), 0.57(±1.13), 0.53(±1.04), 0.68(±0.91),0.55(±0.63). That means for frequemcy of “Feeder 2” on days 0-6respectivley (trays were removed on day 7) are 0.21(±0.5), 0.14(±0.53),0.37(±0.66), 0.25(±0.64), 0.23(±0.67), 0.37(±0.71), and 0.04(±0.28).***Behaviors categorized as “Other” or “Out of view” were alsoinfrequent that the data could not be analyzed, relaxed convergencecriteria was attemped 10⁻⁴. The mean for frequency of “Other” behaviorfor days 0-8 respectively are 0(±0), 0(±0), 0.27(±0.59), 0.29(±0.53),0.26(±0.71), 0.17(±0.47), 0.17(±0.43), 0(±0), and 0(±0). “Out of view”frequency means on days 0-8, respectively, are 0.11(±0.31), 0.36(±1.08),0.27(±0.59), 0.29(±0.53), 0.55(±1.01), 0.46(±0.77), 0.27(±0.66),0.1(±0.36), and 0.05(±0.21).

i. Overall Summary: The implementation of the laser device as a form ofenvironmental enrichment led to increased weight gains, improved feedconversion, and improved average daily gains, particularly in the last 2weeks of growth as well as overall comparisons in our broiler flockexposed to laser enrichment. Birds in the laser group also showed lessnon-interacting behaviors with a human in their pen over time, displayedin the willingness to approach data. Our data imply that having thedaily laser activity did not have a significant impact on the occurrenceof breast blisters or footpad dermatitis, ammonia quantity in the air,litter quality, walking lameness prevalence, or bone mineral density orcontent of the tibia. While data regarding the bird behavior isforthcoming, we can conclude from our performance data that having thelaser device led birds to the feeder to eat more often, reflected intheir significantly increased intake and gains. A major finding from thebehavioral results were that laser enriched birds were more active bothin daily 4 minute recorded observations in days 1-8 as well as weeklyobservations in weeks 2 through 6. For example, in the first 8 days oflife, active percent of time in control was 6.3% and laser enriched was14.1%, representing a 55% increase in time spent active during 4 minuteobservation periods (P<0.0001). On a weekly basis over time (weeks 1-6;1 day of recorded observation/week), control birds spent an average of4.55% active vs 7.49% in enriched birds during the 4 minute observationperiod (P<0.0001), representing a 30% overall average increase in activetime during 4 minute recorded observation periods. In forthcoming data,we also find that birds receiving laser enrichment retain increasedactivity in both duration and frequency. In addition, the laser did notadversely affect drinking or feeder behavior. It is also important thatthis increased activity did not stir up the litter to the degree thatair or litter quality was negatively affected, or that bird foot orbreast health was compromised. This addition to the environment ofbroilers, in our research conditions, can have a significant positiveeffect on bird performance without negatively affecting broiler birdwelfare.

V. OPTIONS AND ALTERNATIVES

As mentioned, the examples above are neither inclusive nor exclusive ofall forms and embodiments that invention or its various aspects cantake. A number of examples of such possible variations are includedabove or the supporting materials in the Appendices, which areincorporated here by reference.

Some further examples are as follows:

1. Light Sources

Red 650 nm lasers are given by example but are non-limiting. The redlaser spots discussed above have been found efficacious. It is possiblethat other laser sources could at least be operable even if not asefficacious as red laser. Some non-limiting examples are:

-   -   a. Pink    -   b. Green    -   c. Ultraviolet range    -   d. Blue    -   e. Orange    -   f. Yellow    -   g. Magenta    -   h. Burgundy    -   i. Silver (white)    -   j. Combinations of the above-mentioned spectra    -   k. Shades within the above-mentioned spectra (Higher, lower, or        between 370 nm, 445 nm, 508 nm, 565 nm, for example, between 330        and 700 nm).

The color of the light spot is at least, of course, within the lightwavelengths or spectra that are perceivable by the specific poultryinvolved. For example, most poultry have tetrachromatic vision whichincludes both visible and UV spectra. See, e.g.,https://academic.oup.com/bioscience/article/50/10/854/233996/andhttps://doi.org/10.1641/0006-3568(2000)050[0854:TABSEV]2.0.CO;2. In onenon-limiting example, therefore, the light source would include bothwavelengths in visible and in UV spectra. On the other hand, lightwavelengths can be what is shown to be effective to elicit a desiredresponse from the relevant poultry that meets or promotes at least oneof the goals or benefits of the present invention. As such it might bemonochromatic and just in the visible spectrum for the relevant bird(s).But it could include a range or variety of spectra. Brightness and otherlight parameters at the spot can be other design factors to consider.

Some considerations for the designer relative the light source are asfollows:

-   -   a. The dots can be adjusted according to the focus by rotating        the lens of typical laser sources.    -   b. Alternatively, the dots could be projected, moved, and        positioned using a set of mirrors or other reflective surfaces    -   c. A maximum of 5V powered laser is recommended, 3.5 V may be        better but if 5V is used, it should always accompany a heat sink        to avoid over-heating.

A variety of laser sources are available for purposed of the invention.Alternatives to lasers are possible. Any concentration of light into acontrollable beam that can be projected over space and produce a lightspot or dot on a surface at least substantially analogous to a laser arepossibilities. Optics may be needed to get sufficient concentration orcollimation. Such are known to those skilled in the art. Non-limitingexamples include incandescent, high intensity, electrostatic, or gasdischarge, LED or other solid state types, halogen, xenon, or others, solong as they can project a beam of sufficient concentration, intensity,and spectra to effectively produce one or more responses from relevantpoultry in alignment with the invention. Foregoing factors, in additionto practical factors such as cost of the sources, cost of energy toproduce sufficient beams and spots from the sources, cost and complexityof any ancillary components to produce sufficient beams and spots (e.g.optics) from the sources, longevity, robustness in sometimes harshenvironments, and maintenance over time, would be considered by thedesigner. As will be appreciated by those skilled in the art, lasers area good candidate because they are relatively inexpensive both topurchase and operate, they are robust and have a relatively long usefullife, they come in different colors, powers, and other operatingparameters, and they are concentrated. They can be substantiallycollimated and have sufficient intensity over substantial distances toproduce effectively bright and relatively small laser light spots onmany types of surfaces (e.g. clean floors, dirty floors, floors of avariety of materials, and even with dirt or debris on top of thefloors). Furthermore, laser sources effective here can have relativelysmall form factors and weight. Thus, relatively inexpensive componentscan be used to support them relative a surface as well as control andchange their aiming orientation, including slowly to quickly, in smalleror larger increments, and the like.

2. Spot Size

As will be appreciated by those skilled in the art, spot size can vary.The designer would consider a variety of factors. One is that the spotdiameter or largest dimension be relatively small compared to the sizeof poultry involved. One non-limiting range would be 2 to 35 mm acrossthe longest dimension of the spot. With lasers, highly concentrated orcollimated beams are available in off-the-shelve products. Sufficientbrightness at the spot is also available. As is well-known, laser beams,including from relatively low-cost, pen-sized devices can travelsubstantial distances (e.g. miles) with sufficient intensity to generatea light spot at a surface at such distances. As will be appreciated fromthe foregoing exemplary embodiments, one reason for a 2 to 25 mm rangerelative to spot size is that it is the approximate range of sizes ofinsects that poultry may predate. Smaller (e.g. ants, mites, or the likeon the order of 2 mm longest dimension) to larger (e.g. insects orcreatures such bigger ants, beetles, flies, etc. as up to and includingon the order of 35 mm) naturally tend to have unpredictable movements(e.g. to avoid predation) and many times quick, start-stop, and changeof direction. Thus, light spots in this general range of sizes canemulate or simulate the size and movement of these natural poultry foodsources. Thus, the size of the light spot selected by the designer forthis purpose is sometimes called relatively small at least in the sensethat it is emulating the size of these typically much smaller creaturesthan the poultry. This is, in at least one sense, in distinction whatmight be considered relatively large for these purposes or sometimesreferred to as a spotlight, as spotlights tend to illuminate a largerarea. One example is a spotlight used in theaters or arenas toilluminate an area that at least subsumes the person towards which it isdirected. A spotlight in that sense is therefore on the same scale ofsize as the creature involved, not a light spot that is usually muchsmaller than the creature involved (here, a bird). Thus, incontradistinction to some other attempts to use lights in the presenceof poultry (see Background of the Invention) which are akin tospotlights, the present invention uses relatively smaller light spots.

3. Actuators

The examples given above are also not limiting. Any type of motioncontrollable device that could manipulate aiming direction of a lasercould be considered. Any set-up that allows motion-control of the laserspots is possible. Examples of non-limiting alternatives are:

-   -   a. Motion controllers;    -   b. motorized gimbal mounts;    -   c. robotic positioners;    -   d. X-y-z positioners.

4. Controller

A rudimentary control circuit with a programmable microprocessor onboardhousing at or near the lasers and actuators as possible. Alternatively,a digital controller apart from the lasers and actuators is possible.This could include wired or wireless communication to such a digitalcontroller. That Digital controller could be a part of or in combinationwith other digital devices. That could include a laptop, smart phone,tablet, or desktop computer. As such, modification of control of thelasers is possible.

As mentioned, any number of regimes of laser spot movement are possible.As indicated, those described above are designed to promote the benefitsto poultry as explained above.

Some considerations for the designer relative the controller are asfollows:

-   -   a. The number of laser sources that can be programmably        controlled:        -   i. can vary from 1 to more than 1, including two or more.            Normally that number can be plural so long as each has a 5V            maximum power.    -   b. Timing:        -   i. Although the timing can be programmed in the Arduino            itself, a timing switch was used instead due to time            constraints.        -   ii. There are many kinds available online, we used Arduino            Uno software (free online).    -   c. Speed programmed for the settings:        -   i. In the specific example, the speed was of the unit 1,            there is no speed metrics available in the actual program. 1            is the minimum and 100 is the maximum, although many servos            don't operate at 100. It was based on trial and error.        -   ii. The value was 1 in the program, which did not estimate a            speed, so we did some measurements based on videos we            recorded.            -   1. We did some calculations based on lasers in the                videos we recorded. We went through and randomly picked                videos from different days (d16, d5, d37, d23) and                measured speed of laser as cms/second the way we would                with walking distance. Three were very close (low                end-typical speed) and one was when the laser zig zagged                really quickly before slowing down again (high end).            -   2. 4 speeds measured were:                -   a. ˜74.24 cm/7 sec=˜10.62 cm/sec                -   b. ˜32.74 cm/4 sec=8.18 cm˜/sec                -   c. ˜138.79 cm/15 sec=˜9.25 cm/sec                -   d. ˜177.8 cm/6 sec=˜29.6 cm/sec            -   3. So, a general estimated speed range would be ˜7.6 to                30.5 cm per second. Of course, there could be faster or                slower movements as this was just an average.            -   Speeds can vary according to designer need or desire.                One non-limiting example is spot movement of 1.0 to 1                cm/sec. This can be at a constant or variable velocity                (including accelerations and decelerations). Another                example is a range of 0.1 to 1 cm/sec over a collective                1 m/min, whether constant or variable velocity over that                minute, or in periods within that minute. Movement can                include or not include start and stops of movement. But                other speeds and movement regimens, including faster,                are possible. The spot may or may not stop for any                duration of time before beginning on a path (or                restarting movement on a path), may flash in the same                location once or several times, or have any combination                of the foregoing. Any of these can be as directed by                random movement patterns.    -   d. Direction change.        -   i. The direction change was based on Random function. Since            the systems were custom-built and programmed, each of them            was tested individually. The X and Y coordinates were            nothing but angles in degrees for each of the two servos. We            tried to estimate the maximum angle needed to sweep through            the pen of 2.4 m. Then we generated a random angle between            the maximum and minimum so that the laser sweeps only within            the pen domain.        -   ii. As discussed herein, the pattern of sport movement can            be completely random during one session and/or between            different sessions. Many digitally controlled actuators            (e.g. digitally controlled motors) have programming            instructions that produce a randomization function. A            designer can produce fully random movement by appropriate            programming or configuration of the components that change            the aiming orientation of a light source or can produce            pseudo-random movement as directed by a randomization based            on intellectual input or data.    -   e. Intermittent starts/stops.        -   i. The start stops are solely dependent on the speed, which            was set at “1” and was random.    -   f. Sessions and Number of Sessions per Time Period        -   i. One design parameter mentioned earlier relates to how            long a laser spot is presented to the birds. It is usually            desirable to limit each session in time as well as number of            sessions per time period to deter the birds from becoming so            conditioned to the spot(s) that it results in habituation.            This could result in the birds not responding in beneficial            ways or at all. But the session time and sessions per day            can vary.

But as understood by those skilled in this technical area, the designercan vary these parameters based on need or desire.

4. Other

Other non-limiting alternatives or additions envisioned are:

-   -   a. A separate wall-socket programmable timer to begin and end        each session may be replaced by programming the digital        controller to implement the same.

For example, the randomized spot movement is described in terms of aspeed or rate of movement and essentially a randomized direction (e.g.both direction and amount of time in any given direction). It is to beunderstood that one speed or rate of movement could be used, or it couldchange at any time as a prat of that randomness in any given session.Furthermore, it is possible to change any of intensity, spot size, andperhaps even color during movement in a session, or between sessions. Itis possible to control movement in a zig-zag pattern (a series of linearmovements of equal or non-equal lengths), but the technique could alsoor alternatively include non-linear movements (curved, part-linear/partnon-linear) so long as the chosen laser and actuator allow the same.

Other non-limiting examples of randomized movement include:

-   -   a. Smooth, controlled lines    -   b. A combination of lines, zig-zags, or arcs    -   c. Variation of speed    -   d. Variation between stationary and movement    -   e. Variation of continuous light, blinking, or any combination        of on/off patterns

As will be appreciated, the designer can elect all types of variationsto spot movement by appropriate configuration of the actuatingcomponents. As indicated in some of the examples, in some cases the spotmovement will simulate or emulate naturally occurring events (e.g.insect movement). But this is not a requirement. As will be furtherappreciated, the spot movement could repeat identically each session,change each session, or change within each session.

What is claimed is:
 1. A method of enriching a set of poultry during oneor more of pre-starter, starter, grower, finisher, maintenance, andbreeding stages in an enclosure around or at a surface at the set ofpoultry comprising: a. placing the set of poultry in the enclosure or atthe surface during at least one of the pre-starter, starter, grower,finisher, maintenance or breeding stages; b. automatically controllingat least one concentrated light beam in the presence of the set ofpoultry in a plurality of enrichment sessions, each enrichment sessionof the plurality of enrichment sessions comprising a predetermined timeperiod spaced apart from other enrichment sessions and furthercomprising: i. projecting the at least one concentrated light beam toproduce a light spot at the surface; and ii. moving the light spot ofeach of the at least one concentrated light beam relative the surfaceaccording to a randomized path with randomized variations of distance,speed, direction, and time of movement along the randomized path from astarting point to an ending point in a manner effective for health,welfare, and commercial value of the set of poultry.
 2. The method ofclaim 1 wherein the light spot has a predetermined: a. size and color;and b. rate of speed of movement, direction of movement, and time ofmovement over the randomized path from starting point to ending point,and between points along the randomized path.
 3. The method of claim 1wherein the light spot comprises an area of on the order of 2 mm to 35mm in largest dimension at the surface.
 4. The method of claim 1 whereinthe enrichment sessions comprise on the order of: a. a plurality of saidtime periods per day; b. a plurality of hours apart; and c. a pluralityof minutes per said time period.
 5. The method of claim 1 wherein themoving further comprises: a. locating a food source at or near thesurface; b. starting the position of the light spot away from the foodsource; c. after the starting position, migrating the light spot towardsthe food source.
 6. The method of claim 1 further comprising: a.blinking the light source on and off for a period in a random patternbefore turning off at the end of at least one of the predetermined timeperiods.
 7. The method of claim 1 wherein the at least one concentratedlight source comprises two concentrated light sources each generated bya separate light source and automatically controlled as in claimclaim
 1. 8. The method of claim 7 wherein the two concentrated lightsources are either (a) independently controlled or (b) dependentlycontrolled relative each other.
 9. The method of claim 1 wherein thepoultry comprise one of chickens, turkeys, quail, ducks, geese,pheasants, and fowl.
 10. The method of claim 1 wherein the surface is afloor, wall, or area in, at, or near a pen, building, portion of abuilding, cage, aviary, or fenced area with a longest dimension rangingfrom feet to tens of feet to hundreds of feet.
 11. The method of claim 1wherein the concentrated light beam comprises a laser beam.
 12. Themethod of claim 1 wherein the moving of the light spot is controlled toenrich one or more of growth rate, weight gain, breast condition, breastmuscling, walking activity, walking distance, bone density, andwell-being of the poultry.
 13. The method of claim 12 wherein the movingof the light spot is controlled to deter increase in lameness.
 14. Asystem for producing poultry comprising: a. an area for raising ormaintaining multiple poultry, in number or species, the area having atleast one enclosure or one surface per set of the multiple poultry; b.at least one light source positioned elevated relative to each saidenclosure or said surface, each said light source capable of projectinga concentrated beam to produce a light spot to a said enclosure or asaid surface; c. one or more actuators operatively connected to each ofthe at least one light source to adjust aiming direction of each of theat least one light source relative a said enclosure or a said surface;and d. a controller operatively in communication with each of the one ormore actuators to automatically instruct movement of each of the atleast one light source during a plurality of enrichment sessions, eachenrichment session of the plurality of enrichment sessions comprising apredetermined time period spaced apart from other enrichment sessions,at least the following: i. on and off of each of the at least one lightsource; and ii. aiming direction of each of the at least one lightsources relative a said enclosure or a said surface according to a pathof movement, wherein the path of movement comprises a randomized pathwith randomized or pseudorandomized variations of distance, speed,direction, and time of movement along the randomized path from astarting point to an ending point in a manner effective for health,welfare, and commercial value of the set of poultry.
 15. The system ofclaim 14 wherein the at least one light source, the one or moreactuators, and the controller are mounted in a housing which includesmounting hardware for elevating the housing at least 1.8 m above thesurface.
 16. The system of claim 14 wherein at least one of the one ormore actuators comprises a motorized pan and tilt assembly.
 17. Thesystem of claim 14 wherein the controller comprises a digitalprogrammable controller.
 18. The system of claim 14 wherein the on andoff of each of the at least one light source comprises predeterminedtime periods comprising on the order of: a. 4 said time periods per day;b. 6 hours apart; and c. 4 minutes per said time period.
 19. The systemof claim 14 wherein the aiming direction comprises: a. moving each saidlight spot of a projected concentrated beam relative the surfaceemulating natural predatory behavior of poultry.
 20. The system of claim14 further comprising first and second areas each with at least one saidenclosure or said surface, each of the first and second adjacent areasfurther enclosed by a larger enclosure, wherein each at least one lightsource comprises a first light source and a second light source, thefirst light source controlled to project a light beam to the first areaand move its beam relative to the at least one said enclosure or saidsurface of the first area, the second light source controlled to projecta light beam to the second area and move its beam relative to the atleast one said enclosure or said surface of the second area.
 21. Thesystem of claim 14 wherein the concentrated beam comprises a laser beam.22. The method of claim 14 wherein the moving of the light spot iscontrolled to enrich one or more of growth rate, weight gain, breastcondition, breast muscling, walking activity, walking distance, bonedensity, and well-being of the poultry.
 23. The method of claim 22wherein the moving of the light spot is controlled to deter increase inlameness.
 24. An apparatus for use in raising poultry comprising: a. ahousing; b. mounting structure adapted to mount the housing in anelevated position relative to a surface of a poultry pen; c. one or moreactuators in the housing; d. a plurality of light sources associatedwith the one or more actuators, each said light source adapted toproduce a concentrated beam from the housing in an aiming directioncontrolled by at least one of said one or more actuators; and e. acontroller operatively connected to each of the plurality of lightsources and each of the one or more actuators, the controller programmedto: i. adjust the aiming directions collectively or individually of theplurality of light sources during predetermined times relative thesurface of the poultry pen; ii. in a randomized or pseudorandomizedmanner effective for health, welfare, and commercial value of thepoultry in the pen.
 25. The apparatus of claim 24 wherein the adjustmentof aiming directions of the plurality of light sources is variableaccording to one or more of direction and speed from a starting time toan end time.
 26. The apparatus of claim 25 wherein the adjustment ofaiming directions of each of the plurality of light sources is variablefrom along a path between the starting time and end time.
 27. Theapparatus of claim 24 wherein the concentrated beam comprises a laserbeam.
 28. The method of claim 24 wherein the moving of the light spot iscontrolled to enrich one or more of growth rate, weight gain, breastcondition, breast muscling, walking activity, walking distance, bonedensity, and well-being of the poultry.
 29. The method of claim 28wherein the moving of the light spot is controlled to deter increase inlameness.